Screaming Penguin - Source Does Matter

I stumbled on PacketFactory because libnet is a requirement for heartbeat. PacketFactory is pretty damn cool. As they put it its a "clearing house for cool-ass network and network security related endeavors." I am particularly impressed with "ngrep" its a GNU grep like utility for network packets. Ahhhh yeah. Of course this can be done with some complicated tcpdump pipes too, but ngrep is simple, sweet and you can ngrep for whatever you want (uh, like grep). Also libnet itself is pretty damn nifty, and firewalk (Firewalk is an active reconnaissance network security tool that attempts to determine what layer 4 protocols a given IP forwarding device will pass), and packit (Packit is a network auditing tool that allows you to monitor, manipulate, and inject customized IP traffic into your network). This site and these tools are just plain cool.

For more check out the cool ass stuff at PacketFactory (cool name too).   The Packetfactory