Manish Arya has contributed an article he has written on using FreeS/WAN to build a VPN. "IPsec has many implementations.one of the common IPsec implementations is Freeswan. IPsec provides encryption and authentication services at the IP (Internet Protocol) level of the network protocol stack. freeswan is a opensource IPsec implementation available from www.freeswan.org. IPsec can protect any traffic carried over IP, unlike other encryption which generally protects only a particular higher-level protocol. . .
Manish Arya has contributed an article he has written on using FreeS/WAN to build a VPN. "IPsec has many implementations.one of the common IPsec implementations is Freeswan. IPsec provides encryption and authentication services at the IP (Internet Protocol) level of the network protocol stack. freeswan is a opensource IPsec implementation available from www.freeswan.org. 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.

When we need a setup in which we want that whatever goes out of network interface (rather a IP address) should be Encrypted, then we can't deploy application specific Encryption implementations. For such setups IPsec is a good solution.

The link for this article located at Manish Arya is no longer available.