hping is a command-line oriented TCP/IP packet assembler/analyzer. The interface
is inspired to the ping(8) unix command, but hping isn't only able to send ICMP
echo requests. It supports TCP, UDP, ICMP and RAW-IP protocols, has a traceroute
mode, the ability to send files between a covered channel, and many other 
features. 
source: http://www.hping.org/hping2.0.0-rc3.tar.gz