Introduction to FreeS/WAN



Table of Contents



Introduction FreeS/WAN quick start guide FreeS/WAN FAQ Installing FreeS/WAN Configuration FreeS/WAN manual pages FreeS/WAN and firewalls Linux FreeS/WAN Troubleshooting Guide Linux FreeS/WAN Compatibility Guide Interoperation with other IPsec implementations Performance of FreeS/WAN Testing FreeS/WAN Kernel configuration for FreeS/WAN Other configuration possibilities Linux FreeS/WAN background FreeS/WAN script examples History and politics of cryptography The IPsec protocols Mailing lists and newsgroups Web links Glossary for the Linux FreeS/WAN project Bibliography for the Linux FreeS/WAN project

IPsec RFCs and related documents Distribution Roadmap: What's Where in Linux FreeS/WAN

Introduction

This section gives an overview of:

This section is intended to cover only the essentials, things you should know before trying to use FreeS/WAN.

For more detailed background information, see the history and politics and IPsec protocols sections.

IPsec, Security for the Internet Protocol

FreeS/WAN is a Linux implementation of the IPsec (IP security) protocols. IPsec provides encryption and authentication services at the IP (Internet Protocol) level of the network protocol stack.

Working at this level, IPsec can protect any traffic carried over IP, unlike other encryption which generally protects only a particular higher-level protocol -- PGP for mail, SSH for remote login, SSL for web work, and so on. This approach has both considerable advantages and some limitations. For discussion, see our IPsec section

IPsec can be used on any machine which does IP networking. Dedicated IPsec gateway machines can be installed wherever required to protect traffic. IPsec can also run on routers, on firewall machines, on various application servers, and on end-user desktop or laptop machines.

Three protocols are used

Our implementation has three main parts:

IPsec is optional for the current (version 4) Internet Protocol. FreeS/WAN adds IPsec to the Linux IPv4 network stack. Implementations of IP version 6 are required to include IPsec. Work toward integrating FreeS/WAN into the Linux IPv6 stack has started.

For more information on IPsec, see our IPsec protocols section, our collection of IPsec links or the RFCs which are the official definitions of these protocols.

Interoperating with other IPsec implementations

IPsec is designed to let different implementations work together. We provide:

The VPN Consortium fosters cooperation among implementers and interoperability among implementations. Their web site has much more information.

Applications of IPsec

Because IPsec operates at the network layer, it is remarkably flexible and can be used to secure nearly any type of Internet traffic. Two applications, however, are extremely widespread:

There is enough opportunity in these applications that vendors are flocking to them. IPsec is being built into routers, into firewall products, and into major operating systems, primarily to support these applications. See our list of implementations for details.

We support both of those applications, and various less common IPsec applications as well, but we also add one of our own:

This is an extension we are adding to the protocols. FreeS/WAN is the first prototype implementation, though we hope other IPsec implementations will adopt the technique once we demonstrate it. See project goals below for why we think this is important.

A somewhat more detailed description of each of these applications is below. Our quickstart section will show you how to build each of them.

Using secure tunnels to create a VPN

A VPN, or Virtual Private N etwork lets two networks communicate securely when the only connection between them is over a third network which they do not trust.

The method is to put a security gateway machine between each of the communicating networks and the untrusted network. The gateway machines encrypt packets entering the untrusted net and decrypt packets leaving it, creating a secure tunnel through it.

If the cryptography is strong, the implementation is careful, and the administration of the gateways is competent, then one can reasonably trust the security of the tunnel. The two networks then behave like a single large private network, some of whose links are encrypted tunnels through untrusted nets.

Actual VPNs are often more complex. One organisation may have fifty branch offices, plus some suppliers and clients, with whom it needs to communicate securely. Another might have 5,000 stores, or 50,000 point-of-sale devices. The untrusted network need not be the Internet. All the same issues arise on a corporate or institutional network whenever two departments want to communicate privately with each other.

Administratively, the nice thing about many VPN setups is that large parts of them are static. You know the IP addresses of most of the machines involved. More important, you know they will not change on you. This simplifies some of the admin work. For cases where the addresses do change, see the next section.

Road Warriors

The prototypical "Road Warrior" is a traveller connecting to home base from a laptop machine. Administratively, most of the same problems arise for a telecommuter connecting from home to the office, especially if the telecommuter does not have a static IP address.

For purposes of this document:

These require somewhat different setup than VPN gateways with static addresses and with client systems behind them, but are basically not problematic.

There are some difficulties which appear for some road warrior connections:

In most situations, however, FreeS/WAN supports road warrior connections just fine.

Opportunistic encryption

One of the reasons we are working on FreeS/WAN is that it gives us the opportunity to add what we call opportuntistic encryption. This means that any two FreeS/WAN gateways will be able to encrypt their traffic, even if the two gateway administrators have had no prior contact and neither system has any preset information about the other.

Both systems pick up the authentication information they need from the DNS (domain name service), the service they already use to look up IP addresses. Of course the administrators must put that information in the DNS, and must set up their gateways with opportunistic encryption enabled. Once that is done, everything is automatic. The gateways look for opportunities to encrypt, and encrypt whatever they can. Whether they also accept unencrypted communication is a policy decision the administrator can make.

This technique can give two large payoffs:

Opportunistic encryption is not (yet?) a standard part of the IPsec protocols, but an extension we are proposing and demonstrating. For details of our design, see links below.

Only one current product we know of implements a form of opportunistic encryption. Secure sendmail will automatically encrypt server-to-server mail transfers whenever possible.

The need to authenticate gateways

A complication, which applies to any type of connection -- VPN, Road Warrior or opportunistic -- is that a secure connection cannot be created magically. There must be some mechanism which enables the gateways to reliably identify each other. Without this, they cannot sensibly trust each other and cannot create a genuinely secure link.

Any link they do create without some form of authentication will be vulnerable to a man-in-the-middle attack. If Alice and Bob are the people creating the connection, a villian who can re-route or intercept the packets can pose as Alice while talking to Bob and pose as Bob while talking to Alice. Alice and Bob then both talk to the man in the middle, thinking they are talking to each other, and the villain gets everything sent on the bogus "secure" connection.

There are two ways to build links securely, both of which exclude the man-in-the middle:

Automatic keying is much more secure, since if an enemy gets one key only messages between the previous re-keying and the next are exposed. It is therefore the usual mode of operation for most IPsec deployment, and the mode we use in our setup examples. FreeS/WAN does support manual keying for special circumstanes. See this section.

For automatic keying, the two systems must authenticate each other during the negotiations. There is a choice of methods for this:

Public key techniques are much preferable, for reasons discussed later, and will be used in all our setup examples. FreeS/WAN does also support auto-keying with shared secret authentication. See this section.

The FreeS/WAN project

For complete information on the project, see our web site, freeswan.org.

In summary, we are implementing the IPsec protocols for Linux and extending them to do opportunistic encryption.

Project goals

Our overall goal in FreeS/WAN is to make the Internet more secure and more private.

Our IPsec implementation supports VPNs and Road Warriors of course. Those are important applications. Many users will want FreeS/WAN to build corporate VPNs or to provide secure remote access.

However, our goals in building it go beyond that. We are trying to help build security into the fabric of the Internet so that anyone who choses to communicate securely can do so, as easily as they can do anything else on the net.

More detailed objectives are:

If we can get opportunistic encryption implemented and widely deployed, then it becomes impossible for even huge well-funded agencies to monitor the net.

See also our section on history and politics of cryptography, which includes our project leader's rationale for starting the project.

Project team

Two of the team are from the US and can therefore contribute no code: The rest of the team are Canadians, working in Canada. ( Why Canada?) The project is funded by civil libertarians who consider our goals worthwhile. Most of the team are paid for this work.

People outside this core team have made substantial contributions. See

Additional contributions are welcome. See the FAQ for details.

Products containing FreeS/WAN

Unfortunately the export laws of some countries restrict the distribution of strong cryptography. FreeS/WAN is therefore not in the standard Linux kernel and not in all CD or web distributions.

FreeS/WAN is, however, quite widely used. Products we know of that use it are listed below. We would appreciate hearing, via the mailing lists, of any we don't know of.

Full Linux distributions

FreeS/WAN is included in various general-purpose Linux distributions, mostly from countries (shown in brackets) with more sensible laws:

For distributions which do not include FreeS/WAN and are not Redhat (which we develop and test on), there is additional information in our compatibility section.

The server edition of Corel Linux (Canada) also had FreeS/WAN, but Corel have dropped that product line.

Office server distributions

FreeS/WAN is also included in several distributions aimed at the market for turnkey business servers:

Firewall

Several distributions intended for firewall and router applications include FreeS/WAN:

There are also several sets of scripts available for managing a firewall which is also acting as a FreeS/WAN IPsec gateway. See this list.

Firewall and VPN products

Several vendors use FreeS/WAN as the IPsec component of a turnkey firewall or VPN product.

Software-only products:

Products that include the hardware: Rebel.com, makers of the Netwinder Linux machines (ARM or Crusoe based), had a product that used FreeS/WAN. The company is in receivership so the future of the Netwinder is at best unclear. PKIX patches for FreeS/WAN developed at Rebel are listed in our web links document.

RPM sets

For some distributions which do not include FreeS/WAN, it may be possible to install using RPM (Redhat Package Manager), rather than going through our more complex procedure.

Some caution is required on this. The RPMs are specific to a Linux distribution and an attempt to use them on another distribution is likely to cause problems.

RPMs for FreeS/WAN 1.91 and Red Hat 7.1 are available for download from Steamballoon. Check there for later versions.

As of version 1.93, the FreeS/WAN distribution incorporates some of the Steamballoon work, providing a facility for building your own RPMs. Details are in our installation document.

Information sources

This HowTo, in multiple formats

FreeS/WAN documentation up to version 1.5 was available only in HTML. Now we ship two formats:

and provide a Makefile to generate other formats if required:

The Makefile assumes the htmldoc tool is available. You can download it from Easy Software. You may need to get source code and change some of the limits in #define MAX_<whatever>statements near the end of its config.h.in file. Otherwise it core dumps when those limits are exceeded on large files such as our glossary.html.

All formats should be available at the following websites:

The distribution tarball has only the two HTML formats.

Note: If you need the latest doc version, for example to see if anyone has managed to set up interoperation between FreeS/WAN and whatever, then you should download the current snapshot. What is on the web is documentation as of the last release. Snapshots have all changes I've checked in to date.

Other documents in the distribution

Text files in the main distribution directory are README, INSTALL, CREDITS, CHANGES, BUGS and COPYING.

FreeS/WAN commands and library routines are documented in standard Unix manual pages, accessible via the man(1) command. We also provide them in HTML, accessible from this index. In the event of disagreement between this HowTo and the man pages, the man pages are more likely correct since they are written by the implementers. Please report any such inconsistency on the mailing list.

The gmp (GNU multi-precision arithmetic) and Libdes (encryption) libraries which we use each have their own documentation. You can find it in those library directories.

Background material

Throughout this documentation, I write as if the reader had at least a general familiarity with Linux, with Internet Protocol networking, and with the basic ideas of system and network security. Of course that will certainly not be true for all readers, and quite likely not even for a majority.

However, I must limit amount of detail on these topics in the main text. If I tried to explain everything here, the result would be completely unreadable.

If one or more of those areas is unknown territory for you, there are plenty of other resources you could look at:

Linux
the Linux Documentation Project or a local Linux User Group and these links
IP networks
Rusty Russell's Networking Concepts HowTo and these links
security
Schneier's book Secrets and Lies and these links

Also, I do make an effort to provide some background material in these documents. All the basic ideas behind IPsec and FreeS/WAN are explained here. Explanations that do not fit in the main text, or that not everyone will need, are often in the glossary, which is the largest single file in this document set. All files are heavily sprinkled with links to each other and to the glossary. If some passage makes no sense to you, try the links.

For other reference material, see the bibliography and our collection of web links.

Of course, no doubt I get this (and other things) wrong sometimes. Feedback via the mailing lists is welcome.

Archives of the project mailing list

Until quite recently, there was only one FreeS/WAN mailing list, and archives of it were: The two archives use completely different search engines. You might want to try both.

More recently we have expanded to five lists, each with its own archive.

More information on mailing lists.

User-written HowTo information

Various user-written HowTo documents are available. The ones covering FreeS/WAN-to-FreeS/WAN connections are:

User-wriiten HowTo material may be especially helpful if you need to interoperate with another IPsec implementation. We have neither the equipment nor the manpower to test such configurations. Users seem to be doing an admirable job of filling the gaps.

Check what version of FreeS/WAN user-written documents cover. The software is under active development and the current version may be significantly different from what an older document describes.

Papers on FreeS/WAN

Two design documents show current team thinking on new developments:

Both documents are works in progress and are frequently revised. For the latest version, see the design mailing list . Comments should go to that list.

There is now an Internet Draft on Opportunistic Encryption by Michael Richardson, Hugh Redelmeier and Henry Spencer. This is a first step toward getting the protocol standardised so there can be multiple implementations of it. Discussion of it takes place on the IETF IPsec Working Group mailing list.

A number of papers giving further background on FreeS/WAN, or exploring its future or its applications, are also available:

Several of these provoked interesting discussions on the mailing lists, worth searching for in the archives.

There are also several papers in languages other than English, see our web links.

License and copyright information

All code and documentation written for this project is distributed under either the GNU General Public License (GPL) or the GNU Library General Public License. For details see the COPYING file in the distribution.

Not all code in the distribution is ours, however. See the CREDITS file for details. In particular, note that the Libdes library and the version of MD5 that we use each have their own license.

Distribution sites

FreeS/WAN is available from a number of sites:

The "munitions" archive of Linux crypto software

There is also an archive of Linux crypto software called "munitions", with its own mirrors in a number of countries. It includes FreeS/WAN, though not always the latest version. Some of its sites are:

Any of those will have a list of other "munitions" mirrors. There is also a CD available.

Links to other sections

For more detailed background information, see:

To begin working with FreeS/WAN, go to:


FreeS/WAN quick start guide

This is a quick guide to and then setting up some common configurations: This should cover everything you need to set up

More complex requirements are covered elsewhere:

However, please read this quick start section first , before tackling the others.

Easy installation

There are two easy ways to install FreeS/WAN:

If your distribution does not include FreeS/WAN and no RPMs are available, see our installation from source document.

Enabling FreeS/WAN

Once you have FreeS/WAN on the system, ensure that it is enabled:
Set your boot loader to get the system booting with the new kernel.
On many systems, you do this by editing lilo.conf(5) and running lilo(8). See the LILO mini-HowTo.
On other systems, you might use grub(8). See the GRUB homepage.
Enable ipsec in your boot scripts.
Typically, this is done with chkconfig(8). If this is unfamiliar territory, see the Power-up to Bash Prompt HowTo.

That's it. FreeS/WAN is installed.

Creating an RSA key

The next step is to generate an RSA key for your machine. These keys are used for machine-to-machine authentication in IPsec negotiations. Any system which will be the endpoint of an IPsec tunnel must have one.

RSA is a public key cryptographic technique. Keys are created as matched pairs. Each pair includes:

For FreeS/WAN, both keys for your system are in the ipsec.secrets(5) file. Maintaining security of this file is essential since it holds your private key.

To generate your key pair, give these commands as root:

        ipsec newhostkey > /etc/ipsec.secrets
        chmod 600 /etc/ipsec.secrets

Key generation may take some time, even on a fast system. Also, it needs a lot of random numbers so you may need to switch consoles and do something like typing a lot of text or running du / > /dev/null. These give random(4) some inputs to work with.

The RSA keys we generate are suitable only for authentication, not for encryption. IPsec uses them only for authentication. See our IPsec section for details.

Setting up opportunistic encryption

Opportunistic encryption makes some aspects of the setup and administration of IPsec easier.

For opportunistic encryption, you do not need to communicate with the administrator of a site before establishing secure communications to that site. In particular, you do not have to send them your keys or collect and authenticate theirs. All you have to do is set up your end correctly and from there on, everything is automatic.

One of the major goals of the FreeS/WAN project is to get opportunistic encryption widely enough deployed that a "FAX effect" comes into play. Neither a FAX machine nor opportunistic encryption is of much value if there are only a few installed, but both become much more useful as the installed base increases.

Widespread deployment of opportunistic encryption appears to be our best hope for making the Internet more secure. See discussion in our introduction.

Initiate-only opportunistic encryption

In this section, we treat the simplest case of opportunistic encryption:

This would apply to a standalone machine, or to a home gateway with some invisible NAT clients.

Given the above conditions, you can set up opportunistic encryption without having access to the DNS reverse map for your machine. The following sections cover situations where one or more of the above restrictions do not apply.

There are two steps:

Once this is done, your system will automatically encrypt whenever it can.

ipsec.conf(5) for initiate-only opportunistism

The ipsec.conf(5) file for this setup is:
# general IPsec setup
config setup
        # Use the default interface
        interfaces=%defaultroute
        # Use auto= parameters in conn descriptions to control startup actions.
        plutoload=%search
        plutostart=%search

# defaults for subsequent connection descriptions
conn %default
        # How to authenticate gateways
        authby=rsasig
        # default is
        # load connection description into Pluto's database
        # so it can respond if another gatway initiates
        # individual connection descriptions may override this
        auto=add

# description for opportunistic connections
conn me-to-anyone
        also=our_stuff             # our system details, stored below
        right=%opportunistic       # anyone we can authenticate
        rightrsasigkey=%dns        # look up their key in DNS
        auto=route                 # set up for opportunistic
        rekey=no                   # let unused connections die

# description of our system
# included in other connection descriptions via also= lines
# must come after the lines that use it
conn our_stuff
        # all connections should use our default route
        # also controls the source address on IPsec packets
        left=%defaultroute
        # our identity for IPsec negotiations
        # must match what is in DNS and ipsec.secrets(5)
        leftid=@xy.example.com

The last line above is the only one that you need to edit for your system. All the rest is identical for any standalone machine doing opportunistic encryption.

There is no need to provide any keys in this file. Your private key is in ipsec.secrets(5) and, for opportunistic encryption, the public keys for remote gateways are all looked up in DNS.

Also note that the left and right designations here are arbitrary. You could reverse them above with no problems.

Initiate-only DNS key

You need to put your system's RSA public key in a DNS record so that systems you communicate with can find it.
Find a helpful DNS administrator
You need the co-operation of a DNS administrator somewhere for this, to place a KEY record so that you can use a name in some domain he or she controls. This need not be either the domain you get your IP address from or a domain that points to your system.

For example, a reverse lookup on the IP address for a home gateway might give 123.adsl.kalamazoo.example.net, and a forward lookup for example.dyndns.org might point to that gateway. You could use either of these names as your ID for IPsec purposes, if the admins at either example.net or dyndns.org co-operate.

If not, you can use any domain whose DNS administrator is willing to help out. You do not need an A record (address record, associating your chosen name with an address) in that domain, only a KEY record.

Generate a KEY record

You can generate a DNS KEY record containing your system's public key with the command:

     ipsec showhostkey
The result should look like this (with the key data trimmed down for clarity):
  ; RSA 2048 bits   xy.example.com   Sat Apr 15 13:53:22 2000
  xy.example.com.   IN   KEY   0x4200 4 1 AQOF8tZ2...+buFuFn/

The name here is taken from ipsec.secrets(5). If it is not what you want, edit that file to correct it, then run ipsec showhostkey again.

The name must also match what you used for rightid= in ipsec.conf(5).

Give this record to the DNS administrator, for insertion into the zone file of the domain.

Firewalling for a standalone system

Firewall rules on a standalone system doing IPsec -- opportunistic, "road warrior" remote access, or both -- can be very simple.

The first step is to allow IPsec packets (IKE on UDP port 500 plus ESP, protocol 50) in and out of your gateway. A script to set up iptables(8) rules for this is:

# edit this line to match the interface you use as default route
# ppp0 is correct for many modem, DSL or cable connections
# but perhaps not for you
world=ppp0
#
# allow IPsec
#
# IKE negotiations
iptables -A INPUT  -p udp -i $world --sport 500 --dport 500 -j ACCEPT
iptables -A OUTPUT -p udp -o $world --sport 500 --dport 500 -j ACCEPT
# ESP encrypton and authentication
iptables -A INPUT  -p 50 -i $world -j ACCEPT
iptables -A OUTPUT -p 50 -o $world -j ACCEPT

Optionally, you could restrict this, allowing these packets only to and from a list of known gateways.

A second firewalling step -- access controls built into the IPsec protocols -- is automatically applied:

Pluto -- the FreeS/WAN keying daemon -- deals with the IKE packets.
Pluto authenticates its partners during the IKE negotiation, and drops negotiation if authentication fails.
KLIPS -- the FreeS/WAN kernel component -- handles the ESP packets.
KLIPS drops outgoing packets
if they are routed to IPsec, but no tunnel has been negotiated for them
KLIPS drops incoming unencrypted packets
if source and destination addresses match a tunnel; the packets should have been encrypted
KLIPS drops incoming encrypted packets
if source and destination address do not match the negotiated parameters of the tunnel that delivers them
if packet-level authentication fails
These errors are logged. See our troubleshooting document for details.

Optionally, you can add a third step using whatever additional firewall rules are required for your situation. These rules can recognise packets emerging from IPsec. They are marked as arriving on an interface such as ipsec0, rather than eth0, ppp0 or whatever. For example, in an iptables(8) rule set, you would use:

-i ipsec+
to specify packets arriving on any ipsec device
-o ipsec+
to specify packets leaving via any ipsec device
It is therefore straightforward to apply whatever additional filtering you like to these packets.

Testing opportunistic connections

To check that opportunistic encryption is working, point a browser to oetest.freeswan.org, a host we have set up to do opportunistic encryption for testing. A link there will tell you whether or not you have an encrypted connection.

If using a bowser is inconvenient, take these steps:

You should see a tunnel to the opportunistic host.

When FreeS/WAN cannot set up an opportunistic connection, and no explicit tunnel has been configured, its default is to allow the traffic through in the clear. For the non-opportunistic host, you should see a %pass eroute (IPsec route), the FreeS/WAN mechanism that implements that default.

Accepting incoming requests for opportunistic encryption

If you need to let others inititiate encrypted connections to your system -- for example, if you run services on your machine and want remote clients to be able to access them securely -- then you need to do a bit more.

There are two steps in the setup.

Both need to be a little different than in the initiate-only case.

For incoming connections, you are not the initiator so you cannot use the first message to tell the other end the identity you wish to use. You must be able to handle having the other end identify you by IP address. In many cases, that will be all the remote gateway knows.

ipsec.conf(5) to accept incoming opportunistic

Only one change is need in the ipsec.conf(5) file. You use an IP address instead of a name as your identity. For example, with the address 1.2.3.4, the section describing your system becomes:
# description of our system
# included in other connection descriptions via also= lines
# must come after the lines that use it
conn our_stuff
        # all connections should use our default route
        # also controls the source address on IPsec packets
        left=%defaultroute
        # our identity for IPsec negotiations
        # must match what is in DNS and ipsec.secrets(5)
        leftid=1.2.3.4

You must make a matching change in ipsec.secrets(5), so that the identifier for your secret key is also "1.2.3.4".

DNS for incoming opportunistic connections

To accept incoming connections, you need to put a KEY record in the DNS reverse map for your gateway. The initiator will not always know your gateway's name. It must be possible to look up the key knowing only the IP address.

The record you need looks like this:

  ; RSA 2048 bits   gateway.example.com   Sat Apr 15 13:53:22 2000
  4.3.2.1.in-addr.arpa.   IN   KEY   0x4200 4 1 AQOF8tZ2...+buFuFn/

Generate a record with ipsec showhostkey, and then edit it to insert the IP address.

As always, IP addresses in the reverse map are written backwards. In the above example, the gateway IP address is 1.2.3.4.

Firewalling incoming opportunistic connections

The basic firewalling for IPsec does not change when you support incoming connections as well as connections you initiate. You must still allow IKE (UDP port 500) and ESP (protocol 50) packets to and from your machine, as in the rules given above.

However, there are additional security concerns when you allow incoming opportunistic connections. This creates an additional path to your machine, so you need to check your rules to see that this does not provide a means for EvilDoers to bypass protections you have set up on other paths.

In particular, look at any rules you have that depend on interfaces, rules using -i ppp+, -o eth1 or similar expressions. You may need analogous rules for your ipsec interfaces.

An opportunistic gateway

Next we expand from a standalone system (which protects only its own traffic) to a gateway (which protects traffic for other systems).

There is one special case in which gateway configuration is quite simple -- if all the machines behind the gateway are hidden from the Internet. We describe that first, then go on to describe gateways for visible clients.

NAT for hidden clients

If your gateway uses NAT to allow machines to access the Internet without having their own routable IP addresses, then from the point of view of anyone else on the Internet:

For purposes of IPsec across the Internet, your gateway can be treated as a standalone machine. Consequently, For a more detailed discussion of NAT, see our background section.

Gateway for visible clients

Many gateways will need to support client systems which have routable addresses and are visible to the Internet. This involves:

ipsec.conf(5) for an opportunistic gateway

You need only make a few additions to in the ipsec.conf(5) file:

The additions to the ipsec.conf(5) file might be:

# opportunistic connections for client systems
# our gateway will build opportunistic tunnels on behalf of any
# machine in the specified subnet
conn subnet-to-anyone
        also=gate_stuff             # our system details, stored below
        also=public_subnet          # subnet description, below
        auto=route                  # set up for opportunistic
        right=%opportunistic        # anyone we can authenticate via DNS
        rekey=no                    # let unused connections die

# description of the subnet this gateway encrypts for
# numbers used here are arbitrary, just for example
conn public_subnet
       leftsubnet=42.42.42.0/24 

There is one small thing to be careful of here. An also= line must appear in the file before the conn it references, so the first section above must appear before conn gate_stuff.

Supporting additional subnets
If required, a gateway can easily provide this service for more than one subnet. You just add a connection description and a subnet description for each. For example, leaving everything else above unchanged, you could add these sections:
# opportunistic connections for additional systems
conn second-to-anyone
        also=gate_stuff             # our system details, stored below
        also=second_subnet          # subnet description, below
        right=%opportunistic        # anyone we can authenticate via DNS
        rekey=no                    # let unused connections die

# description of a second subnet this gateway encrypts for
# numbers used here are arbitrary, just for example
conn second_subnet
       leftsubnet=101.102.103.0/24 

again, you need a little care so that also= lines always come before the sections they reference.

The subnets used in these descriptions need not correspond to physical subnets. This is discussed in more detail in our advanced configuration document.

DNS entries for an opportunistic gateway

We assume you already have a KEY record in the reverse map so your gateway can accept incoming connections as described above.

For the gateway to provide an opportunistic encryption service for other systems, it must be possible for the initiator of an IPsec connection to:

This is done by adding a TXT record to the reverse map for the endpoint. The record (with key shortened) looks like this:
        ; RSA 2048 bits  gateway.example.com   Sat Apr 15 13:53:22 2000
        IN TXT  "X-IPsec-Server(10)=1.2.3.4 AQOF8tZ2...+buFuFn/"
This record must be generated on the gateway so it can get the key from ipsec.secrets(5). The command is:
     ipsec showhostkey --txt 1.2.3.4
You must supply the gateway IP address on the command line.

One of these records is required in the reverse map for each system using this gateway for opportunistic IPsec. You insert it in the reverse map part of the zone file right after the line for that system's IP address, so part of the file might look like this:

      1.42.42.42.in-addr.arpa. IN PTR arthur.example.com 
        ; RSA 2048 bits  gateway.example.com   Sat Apr 15 13:53:22 2000
        IN TXT  "X-IPsec-Server(10)=1.2.3.4 AQOF8tZ2...+buFuFn/"
      2.42.42.42.in-addr.arpa. IN PTR ford.example.com 
        ; RSA 2048 bits  gateway.example.com   Sat Apr 15 13:53:22 2000
        IN TXT  "X-IPsec-Server(10)=1.2.3.4 AQOF8tZ2...+buFuFn/"
      3.42.42.42.in-addr.arpa. IN PTR trillian.example.com 
        ; RSA 2048 bits  gateway.example.com   Sat Apr 15 13:53:22 2000
        IN TXT  "X-IPsec-Server(10)=1.2.3.4 AQOF8tZ2...+buFuFn/"
You need one TXT record per client, but the TXT records can all be identical.

Firewalling for gateways

On a gateway, the IPsec-related firewall rules applied for input and output on the Internet side are exactly as shown above. A gateway exchanges exactly the same things -- UDP 500 packets and IPsec packets -- with other gateways that a standalone system does, so it can use exactly the same firewall rules as a standalone system would.

However, on a gateway there are additional things to do:

You need additional rules to handle these things. For example, adding some rules to the set shown above we get:

# edit this line to match the interface you use as default route
# ppp0 is correct for many modem, DSL or cable connections
# but perhaps not for you
world=ppp0
#
# edit these lines to describe your internal subnet and interface
localnet=42.42.42.0/24
internal=eth1
#
# allow IPsec
#
# IKE negotiations
iptables -A INPUT  -p udp -i $world --sport 500 --dport 500 -j ACCEPT
iptables -A OUTPUT -p udp -o $world --sport 500 --dport 500 -j ACCEPT
# ESP encrypton and authentication
iptables -A INPUT  -p 50 -i $world -j ACCEPT
iptables -A OUTPUT -p 50 -o $world -j ACCEPT
#
# packet forwarding for an IPsec gateway
# simplest possible rules
$ forward everything, with no attempt to filter
#
# handle packets emerging from IPsec
# ipsec+ means any of ipsec0, ipsec1, ...
iptables -A FORWARD -d $localnet -i ipsec+ -j ACCEPT
# simple rule for outbound packets
# let local net send anything
# IPsec will encrypt some of it
iptables -A FORWARD -s $localnet -i $internal -j ACCEPT 

On a production gateway, you would no doubt need tighter rules than the above. For details, see:

"Road Warrior" remote access

A common requirement is for pre-configured connections between a specfic network and some set of remote machines. For example, an office network will often need to provide remote access services for:

We refer to the remote machines as "Road Warriors". For purposes of IPsec, anyone with a dynamic IP address is a road warrior.

Of course, if both the warrior and the gateway at the office are set up for opportunistic encryption, then you may not need the pre-configured connection. Here we assume that you do need it. For example:

This section has three sub-sections:

On either end, the opportunistic setup is unaffected by this. You leave it in place so both systems can continue to do opportunistic encryption with everyone but each other.

Information exchange

To set up an explicitly configured connection, you need some information about the system on the other end.

Connection descriptions use left and right to designate the two ends. We adopt the convention that, from the gateway's point of view left=local and right=remote.

The gateway administrator needs to know some things about each Road Warrior:

To get this information, in a format suitable for insertion directly into the gateway's ipsec.conf(5) file, issue this command on the Warrior machine:

        ipsec showhostkey --right
The output should look like this (with the key shortened for easy reading):
        rightid=@xy.example.com
        rightrsasigkey=0s1LgR7/oUM...

The Road Warrior needs to know:

which can be generated by running ipsec showhostkey --left on the gateway. Each Warrior must also know:

This information should be provided in a convenient format, ready for insertion in the Warrior's ipsec.conf(5) file. For example:

        left=1.2.3.4
        leftsubnet=42.42.42.0/24
        leftid=@gateway.example.com
        leftrsasigkey=0s1LgR7/oUM...

The gateway administrator typically needs to generate this only once. The same file can be given to all Warriors.

Of course it is also possible to provide different versions (in particular, access to differnet subnets) to different groups of Warriors. See our advanced configuration document.

Setup on the Road Warrior machine

To set up a Road Warrior machine, we start from the opportunistic imitiator setup shown above.

We need to add a connection description for the pre-configured tunnel. Since we want to be right in that description, we reverse the opportunistic description so we are right there too.

Connection description for a pre-configured tunnel

We insert the new connection description before the conn our_stuff section, so that it can use an also= line referring to that section.
# description for opportunistic connections
# reversed from previous example
conn me-to-anyone
        also=our_stuff             # our system details, stored below
        left=%opportunistic        # anyone we can authenticate
        leftrsasigkey=%dns         # look up their key in DNS
        auto=route                 # set up for opportunistic
        rekey=no                   # let unused connections die

# pre-configured link to office network
# added for this example
conn us-to-office
        also=our_stuff             # our system details, stored below
        #
        # information obtained from office system admin
        # goes to the right of the = signs in these lines
        # values shown here are just for example
        # 
        left=1.2.3.4                # gateway IP address
        lefttsubnet=42.42.42.0/24   # the office network
        leftid=@gateway.example.com
        # real keys are much longer than shown here
        leftrsasigkey=0s1LgR7/oUM...

# description of our system
# included in other connection descriptions via also= lines
# must come after the lines that use it
# reversed from previous example
conn our_stuff
        # all connections should use our default route
        # also controls the source address on IPsec packets
        right=%defaultroute
        # our identity for IPsec negotiations
        # must match what is in DNS and ipsec.secrets(5)
        righttid=@xy.example.com

Everything else remains as it was when we had only opportunistic connections.

We could easily add more connections as required, perhaps one each for his office, her office, the kid's school, ... The file would grow longer, but nothing already in the file would need to change.

Road Warrior support on an office gateway

Adding road warrior support so people can connect remotely to your office network is straightforward.

We start from the opportunistic gateway setup shown above.

Putting connection descriptions in separate files

You could put a complete connection description for each Warrior in your ipsec.conf(5) file, but this makes for a rather unmanageable file if you have many Warriors.

Instead, we suggest you give each warrior its own file, choosing some directory and naming convention that suits your system and style.

For this example, we use the directory /etc/ipsec.road and use filenames based on IPsec ID, so the Warrior using ID xy.example.com gets a file named xy.conf.

Using such files, you need add only one line to ipsec.conf(5). With our naming convention, the line is:

      include /etc/ipsec.road/*.conf

FreeS/WAN will then read all those files and behave as if they were part of the ipsec.conf(5) file.

This needs to come before the conn gate_stuff section, so that the Warriors' connection descriptions can use also=gate_stuff . A convenient place for the line is right after the conn %default section.

Each of the Road Warrior files then contains a connection description for that Warrior. For example:

# connection description for Road Warrior "xy"
conn gate-xy
        # use the gateway description in ipsec.conf(5)
        also=gate_stuff
        # allow connection attempt from any address
        # attempt fails if caller cannot authenticate
        right=%any
        # authentication information
        rightid=@xy.example.com
        rightrsasigkey=0s1LgR7/oUM...

With this technique, it becomes fairly simple to administer a gateway that supports many Road Warriors. For example:

To add a new user, simply add a suitable file.

To disable an account -- for example if a key is compromised -- first remove the file, then take any existing connection down with:

        ipsec auto --down connection
and delete it from Pluto's internal database with:
        ipsec auto --delete connection

If you have many users, it would be worthwhile to write scripts to automate such tasks.

Network-to-network VPN

Often it is useful to have explicitly configured IPsec tunnels between different offices of an organisation, or between organisations that have joint projects.

Of course, if both offices are set up for opportunistic encryption and the security policies in place allow you to use that, explicitly configured tunnels become unnecessary. However, this will not always be the case.

Gateway setup for net-to-net

Adding up a network-to-network tunnel does not require any change to the opportunistic or Road warrior parts of your ipsec.conf(5). You can keep those parts exactly as shown above.

Of course, a network-to-network tunnel requires its own connection description, so you have to add that. There are two ways to do this.

identical connection description on the two ends
needs to specify more detail so the machine can figure out which end it is on
slightly different descriptions on the two ends
needs less detail, but you need to manage two descriptions
Choose whichever is more convenient to administer in your environment.

A connection description that works on either end

Here is a network-to-network tunnel description from our examples file:
# sample tunnel
# The network here looks like:
#   leftsubnet====left----leftnexthop......rightnexthop----right====rightsubnet
# If left and right are on the same Ethernet, omit leftnexthop and rightnexthop.
conn sample
        # left security gateway (public-network address)
        left=10.0.0.1
        # next hop to reach right
        leftnexthop=10.44.55.66
        # subnet behind left (omit if there is no subnet)
        leftsubnet=172.16.0.0/24
        # right s.g., subnet behind it, and next hop to reach left
        right=10.12.12.1
        rightnexthop=10.88.77.66
        rightsubnet=192.168.0.0/24
        auto=start
If you give an explicit IP address for left (and left and right are not directly connected), then you must specify leftnexthop (the router which left sends packets to in order to get them delivered to right). Similarly, you may need to specify rightnexthop (vice versa).

The *nexthop parameters are needed because of an unfortunate interaction between FreeS/WAN and the kernel routing code. They will be eliminated in a future release, but perhaps not soon. We know they should go, but getting them out is not a simple problem.

This description can be generated on either machine and simply inserted in the ipsec.conf(5) file on the other. No change is required or desired.

Using slightly different descriptions

Provided both machines do IPsec over the interface that is their default route to the Internet (a common case, but by no means the only one) you can simplify the description somewhat.

When using left=%defaultroute, you do not need to specify leftnexthop. left does not need to know rightnexthop either, so on left the connection description can be:

conn sample
        # left security gateway (public-network address)
        left=%defaultroute
        # subnet behind left (omit if there is no subnet)
        leftsubnet=172.16.0.0/24
        # right s.g., subnet behind it
        right=10.12.12.1
        rightsubnet=192.168.0.0/24
        auto=start
On right it is:
conn sample
        # left security gateway (public-network address)
        left=10.0.0.1
        # subnet behind left (omit if there is no subnet)
        leftsubnet=172.16.0.0/24
        # right s.g., subnet behind it
        right=%defaultroute
        rightsubnet=192.168.0.0/24
        auto=start

What next?

At this point, we have covered setup for opportunistic encryption and for simple cases of Road warrior and VPN connections. You have several choices for what to look at next:


FreeS/WAN FAQ

This is a collection of questions and answers, mostly taken from the FreeS/WAN mailing list. See the project web site for more information. All the FreeS/WAN documentation is online there.

Contributions to the FAQ are welcome. Please send them to the project mailing list.


Index of FAQ questions


What is FreeS/WAN?

FreeS/WAN is a Linux implementation of the IPsec protocols, providing security services at the IP (Internet Protocol) level of the network.

For more detail, see our introduction document or the FreeS/WAN project web site.

How do I report a problem or seek help?

See our troubleshooting document. It may guide you to a solution. If not, see its problem reporting section.

Basically, what it says is give us the output from ipsec barffrom both gateways. Without full information, we cannot diagnose a problem. However, ipsec barf produces a lot of output. If at all possible, please make barfs accessible via the web or FTP rather than sending enormous mail messages.

Use the mailing list for problem reports, rather than mailing developers directly. This gives you access to more expertise, including users who may have encountered and solved the same problems. In particular, for problems involving interoperation with another IPsec implementation, the users often know more than the developers.

Using the list may also be important in relation to various cryptography export laws. A US citizen who provides technical assistance to foreign cryptographic work might be charged under the arms export regulations. Such a charge would be easier to defend if the discussion took place on a public mailing list than if it were done in private mail.

Generic questions

This is too complicated. Isn't there an easier way?

There are a number of Linux distributions or firewall products which include FreeS/WAN. See this list. Using one of these, chosen to match your requirements and budget, may save you considerable time and effort. (If you don't know your requirements, start by reading Schneier's Secrets and Lies. That gives the best overview of security issues I have seen.)

If you want the help of a contractor, or to hire staff with FreeS/WAN expertise, you could:

For companies offerring support, see the next question.

Can I get commercial support for this product?

Many of the distributions or firewall products which include FreeS/WAN (see this list) come with commercial support or have it available as an option.

Various companies specialize in commercial support of open source software. Our project leader was a founder of the first such company, Cygnus Support. It has since been bought by Redhat. Another such firm is Linuxcare.

Can I modify FreeS/WAN to ...?

You are free to modify FreeS/WAN in any way. See the discussion of licensing in our introduction document.

Can I contribute to the project?

In general, we welcome contributions from the community. Various contributed patches, either to fix bugs or to add features, have been incorporated into our distribution. Other patches, not yet included in the distribution, are listed in our web links section.

Users have also contributed heavily to documentation, both by creating their own HowTos and by posting things on the mailing lists which I have quoted in these HTML docs.

There are, however, some caveats.

FreeS/WAN is being implemented in Canada, by Canadians, largely to ensure that is it is entirely free of export restrictions. See this discussion. We cannot accept code contributions from US residents or citizens, not even one-line bugs fixes. The reasons for this were recently discussed extensively on the mailing list, in a thread starting here.

Not all contributions are of interest to us. The project has a set of fairly ambitious and quite specific goals, described in our introduction. Contributions that lead toward these goals are likely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which our testing did not turn up. It is also possible you will be bitten by a bug in the driver that shows up only with our loads. Another FAQ section describes the commonest of this class of problem.

If IP works on your interface and FreeS/WAN doesn't, seek help on the mailing lists.

Does FreeS/WAN support ...

For a discussion of which parts of the IPsec specifications FreeS/WAN does and does not implement, see our compatibility document.

For information on some often-requested features, see below.

Does FreeS/WAN support site-to-site VPN applications

Yes, FreeS/WAN can be used to build site-to-site Virtual Private Networks.

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Does FreeS/WAN support remote users connecting to a LAN

Yes, FreeS/WAN can be used to connect remote users. In the documentation, we refer to them as "Road Warriors".

This application is discussed in our introduction and an example given in our FreeS/WAN configuration document.

Road warriors using Windows or Macintosh may need an IPsec client program for their machines.

Does FreeS/WAN support wireless networks

Yes, it is a common practice to use IPsec over wireless networksamplkely to be welcomed enthusiastically. Other contributions may be seen as lower priority, or even as a distraction.

Is there detailed design documentation?

There are: The only formal design documents are a few papers in the last category above. All the other categories, however, have things to say about design as well.

Will FreeS/WAN work in my environment?

Is a ... fast enough to handle FreeS/WAN with ... connections?

A quick summary:
FreeS/WAN can run happily on limited machines.
A 486 can handle a T1, ADSL or cable link, though the machine may be breathing hard.
Most requirements can be met
A current (mid-2001) technology PC handling 20 Megabits per second of IPsec processing will still have some cycles available for other tasks.
There are definite limits at the high end
A current high end CPU might handle a loaded T3 at 45 Mbit/second. However, it will not even come close to handling a fully loaded 100 Mbit/second Ethernet link, let alone 155 Mbit/second OC3.
Beyond that, the picture is not clear. Much depends on details of your network, your traffic, and other loads on both machine and net.

See our FreeS/WAN performance document for more detail.

Can FreeS/WAN talk to ...?

The IPsec protocols are designed to support interoperation. In theory, any two IPsec implementations should be able to talk to each other.

In practice, it is considerably more complex. We have a whole interop document devoted to it.

Can different FreeS/WAN versions talk to each other?

Linux FreeS/WAN can interoperate with many IPsec implementations, including earlier versions of Linux FreeS/WAN itself.

In a few cases, there are some complications. See our interoperation document for details.

Will FreeS/WAN run on my version of Linux?

We build and test on Redhat distributions, but FreeS/WAN runs just fine on several other distributions, sometimes with minor fiddles to adapt to the local environment. Details are in our compatibility document. Also, some distributions or products come with FreeS/WAN included.

FreeS/WAN is intended to run on all CPUs Linux supports . As of June 2000, we know of it being used in production on x86, ARM, Alpha and MIPS. It has also had successful tests on PPC and SPARC, though we don't know of actual use there. Details are in our compatibility document.

FreeS/WAN has been tested on multiprocessor Intel Linux and worked there. Note, however, that we do not test this often and have never tested on multiprocessor machines of other architectures.

Will FreeS/WAN work on an older kernel?

It might, but we strongly recommend using a recent 2.2 or 2.4 series kernel. Sometimes the newer versions include security fixes which can be quite important on a gateway.

The precise kernel versions supported by a particular FreeS/WAN release are given in the README file of that release.

See the follwing question for more on kernels.

Will FreeS/WAN run on the latest kernel version?

Sometimes yes, but quite often, no.

Kernel versions supported are given in the README file of each FreeS/WAN release. Typically, they are whatever production kernels were current at the time of our release (or shortly before; we might release for kernel n just as Linus releases n+1). Often FreeS/WAN will work on slightly later kernels as well, but of course this cannot be guaranteed.

For example, FreeS/WAN 1.91 was released for kernels 2.2.19 or 2.4.5, the current kernels at the time. It also worked on 2.4.6, 2.4.7 and 2.4.8, but 2.4.9 had changes that caused compilation errors if it was patched with FreeS/WAN 1.91.

When such changes appear, we put a fix in the FreeS/WAN snapshots, and distribute it with our next release. However, this is not a high priority for us, and it may take anything from a few days to several weeks for such a problem to find its way to the top of our kernel programmer's To-Do list. In the meanwhile, you have two choices:

We don't even try to keep up with kernel changes outside the main 2.2 and 2.4 branches, such as the 2.4.x-ac patched versions from Alan Cox or the 2.5 series of development kernels. We'd rather work on developing the FreeS/WAN code than on chasing these moving targets. We are, however, happy to get patches for problems discovered there.

See also the Choosing a kernel section of our installation document.

Will FreeS/WAN work on ... network hardware?

IPsec is designed to work over any network that IP works over, and FreeS/WAN is intended to work over any network interface hardware that Linux supports.

If you have working IP on some unusual interface -- perhaps Arcnet, Token Ring, ATM or Gigabit Ethernet -- then IPsec should "just work".

That said, practice is sometimes less tractable than theory. Our testing is done almost entirely on:

If you have some other interface, especially an uncommon one, it is entirely possible you will get bitten by a FreeS/WAN bug which