cipherdyne.org — Most Port Knocking systems only allow access to the local system by reconfiguring your firewall policy for local access. This link shows you how fwknop can add port forwarding NAT rules to your iptables policy so you can access internal systems directly from external networks without having to login to the gateway system at all.
Apr 6, 2008 View in Crawl 4
grippApr 6, 2008
good info