Nest is a secure IP VPN tunnel for FreeBSD. It
connects two LANs over an insecure WAN. Nest works
on the IP packet level. Its features include
packet authentication and integrity checking (with
96-bit SHA1-derived HMAC), packet encryption (with
Blowfish and 160-bit key CBC mode), replay
protection, adjustable packet queuing, and
compression. The VPN traffic appears on the WAN as
a bidirectional stream of IP packets or as a
unidirectional ICMP request/response stream. The
latter case allows the establishment of VPN
tunnels through certain firewalls.
