netmon
Mausezahn is a free fast traffic generator written in C which allows you to send nearly every possible and impossible packet.
It is mainly used to test VoIP or multicast networks but also for security audits to check whether your systems are hardened enough for specific attacks.
herbert@perihel.at
Herbert Haas
http://www.perihel.at/sec/mz/ChangeLog
http://www.perihel.at/sec/mz/mzguide.html
http://www.perihel.at/sec/mz/mops.html