Some interesting site :
- OpenBSD section in kernel panic (Redundant firewalls with OpenBSD, CARP and pfsync, OpenBSD as a mail server, The Squid and the Blowfish, OpenBSD as a domain name server, Network monitoring with Nagios and OpenBSD, OpenBSD as a Primary Domain Controller)
- Netflow connection, These tools provide a method of collection and display of NetFlow information.
- Netflow information, Cisco whitepaper