Table of Contents
Introduction
IPsec, Security for the Internet Protocol
Interoperating with other IPsec implementations
Advantages of IPsec
Applications of IPsec
The need to authenticate gateways
The FreeS/WAN project
Project goals
Project team
Products containing FreeS/WAN
Full Linux distributions
Linux kernel distributions
Office server distributions
Firewall distributions
Firewall and VPN products
Information sources
This HowTo, in multiple formats
RTFM (please Read The Fine Manuals)
Other documents in the distribution
Background material
Archives of the project mailing list
User-written HowTo information
Papers on FreeS/WAN
License and copyright information
Distribution sites
Primary site
Mirrors
The "munitions" archive of Linux crypto software
Links to other sections
Upgrading to FreeS/WAN 2.x
New! Built in Opportunistic connections
Upgrading Opportunistic Encryption to 2.01 (or later)
New! Policy Groups
New! Packetdefault Connection
FreeS/WAN now disables Reverse Path Filtering
Revised ipsec.conf
No promise of compatibility
Most ipsec.conf files will work fine
Backward compatibility patch
Details
Upgrading from 1.x RPMs to 2.x RPMs
Quickstart Guide to Opportunistic Encryption
Purpose
OE "flag day"
Requirements
RPM install
Download RPMs
Check signatures
Install the RPMs
Test
Our Opportunistic Setups
Full or partial opportunism?
Initiate-only setup
Restrictions
Create and publish a forward DNS record
Test that your key has been published
Configure, if necessary
Test
Full Opportunism
Put a TXT record in a Forward Domain
Put a TXT record in Reverse DNS
Test your DNS record
No Configuration Needed
Consider Firewalling
Test
Test
Testing opportunistic connections
Now what?
Notes
Troubleshooting OE
Known Issues
How to Configure Linux FreeS/WAN with Policy Groups
What are Policy Groups?
Built-In Security Options
Using Policy Groups
Example 1: Using a Base Policy Group
Example 2: Defining IPsec Security Policy with Groups
Example 3: Creating a Simple IPsec VPN with the private Group
Example 4: New Policy Groups to Protect a Subnet
Example 5: Adding a Subnet to the VPN
Appendix
Our Hidden Connections
Custom Policy Groups
Disabling Opportunistic Encryption
FreeS/WAN FAQ
Index of FAQ questions
What is FreeS/WAN?
How do I report a problem or seek help?
Can I get ...
Can I get an off-the-shelf system that includes FreeS/WAN?
Can I hire consultants or staff who know FreeS/WAN?
Can I get commercial support?
Release questions
What is the current release?
When is the next release?
Are there known bugs in the current release?
Modifications and contributions
Can I modify FreeS/WAN to ...?
Can I contribute to the project?
Is there detailed design documentation?
Will FreeS/WAN work in my environment?
Can FreeS/WAN talk to ...?
Can different FreeS/WAN versions talk to each other?
Is there a limit on throughput?
Is there a limit on number of tunnels?
Is a ... fast enough to handle FreeS/WAN with my loads?
Will FreeS/WAN work on ... ?
Will FreeS/WAN run on my version of Linux?
Will FreeS/WAN run on non-Intel CPUs?
Will FreeS/WAN run on multiprocessors?
Will FreeS/WAN work on an older kernel?
Will FreeS/WAN run on the latest kernel version?
Will FreeS/WAN work on unusual network hardware?
Will FreeS/WAN work on a VLAN (802.1q) network?
Does FreeS/WAN support ...
Does FreeS/WAN support site-to-site VPN ( Virtual Private Network) applications?
Does FreeS/WAN support remote users connecting to a LAN?
Does FreeS/WAN support remote users using shared secret authentication?
Does FreeS/WAN support wireless networks?
Does FreeS/WAN support X.509 or other PKI certificates?
Does FreeS/WAN support user authentication (Radius, SecureID, Smart Card...)?
Does FreeS/WAN support NAT traversal?
Does FreeS/WAN support assigning a "virtual identity" to a remote system?
Does FreeS/WAN support single DES encryption?
Does FreeS/WAN support AES encryption?
Does FreeS/WAN support other encryption algorithms?
Can I ...
Can I use policy groups along with explicitly configured connections?
Can I turn off policy groups?
Can I reload connection info without restarting?
Can I use several masqueraded subnets?
Can I use subnets masqueraded to the same addresses?
Can I assign a road warrior an address on my net (a virtual identity)?
Can I support many road warriors with one gateway?
Can I have many road warriors using shared secret authentication?
Can I use Quality of Service routing with FreeS/WAN?
Can I recognise dead tunnels and shut them down?
Can I build IPsec tunnels over a demand-dialed link?
Can I build GRE, L2TP or PPTP tunnels over IPsec?
... use Network Neighborhood (Samba, NetBIOS) over IPsec?
Life's little mysteries
I cannot ping ....
It takes forever to ...
I send packets to the tunnel with route(8) but they vanish
When a tunnel goes down, packets vanish
The firewall ate my packets!
Dropped connections
Disappearing %defaultroute
TCPdump on the gateway shows strange things
Traceroute does not show anything between the gateways
Testing in stages
Manually keyed connections don't work
One manual connection works, but second one fails
Manual connections work, but automatic keying doesn't
IPsec works, but connections using compression fail
Small packets work, but large transfers fail
Subnet-to-subnet works, but tests from the gateways don't
Compilation problems
gmp.h: No such file or directory
... virtual memory exhausted
Interpreting error messages
route-client (or host) exited with status 7
SIOCADDRT:Network is unreachable
ipsec_setup: modprobe: Can't locate module ipsec
ipsec_setup: Fatal error, kernel appears to lack KLIPS
ipsec_setup: ... failure to fetch key for ... from DNS
ipsec_setup: ... interfaces ... and ... share address ...
ipsec_setup: Cannot adjust kernel flags
Message numbers (MI3, QR1, et cetera) in Pluto messages
Connection names in Pluto error messages
Pluto: ... can't orient connection
... we have no ipsecN interface for either end of this connection
Pluto: ... no connection is known
Pluto: ... no suitable connection ...
Pluto: ... no connection has been authorized
Pluto: ... OAKLEY_DES_CBC is not supported.
Pluto: ... no acceptable transform
rsasigkey dumps core
!Pluto failure!: ... exited with ... signal 4
ECONNREFUSED error message
klips_debug: ... no eroute!
... trouble writing to /dev/ipsec ... SA already in use
... ignoring ... payload
unknown parameter name "rightcert"
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FreeS/WAN manual pages
Files
Commands
Library routines
FreeS/WAN and firewalls
Filtering rules for IPsec packets
Firewall configuration at boot
A simple set of rules
Other rules
Published rule sets
Calling firewall scripts, named in ipsec.conf(5)
Scripts called at IPsec start and stop
Scripts called at connection up and down