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. 
While hping was mainly used as a security tool in the past, it can be 
used in many ways by people that don't care about security to test 
networks and hosts.

hping3 adds the TCL scripting feature.

WWW: http://www.hping.org/