When searched on google i got two three options like FreeS/WAN, StrongS/WAN, OpenS/WAN and Open VPN.
The *S/WANs are all IPSec implementations. 2.6 kernels has native IPSec, so you really don't need them anymore. Unless you already have infrastructure that uses them and/or are very familiar with them, I'd just go with Linux native IPSec.
OpenVPN is user-land implementation. Another user-land implementation is VTun.
Both (IPSec and user-land stuff) have advantages and disadvantages. IPSec (in combination with auto-rekeying and x509 certificates) is probably the best way to go, but you'll need to do some reading to understand how it works. On the other hand user-land stuff like VTun is very easy to understand and configure (you can get it up and running in about 10 minutes, even if you are completely new to it). OpenVPN is somewhere in the middle.
-- Aleksandar Milivojevic <amilivojevic@xxxxxx> Pollard Banknote Limited Systems Administrator 1499 Buffalo Place Tel: (204) 474-2323 ext 276 Winnipeg, MB R3T 1L7
