NMap is one of the more famous open source network mappers or security scanners.
Snot is an arbitrary packet generator, that uses snort rules files as its source of packet information.
Nemesis is a command-line network packet crafting and injection utility for UNIX-like and Windows systems built on top of NMap.
LANTraffic V2 and IP Traffic Test & Measure are powerful software testing tools for automatic generation of TCP and UDP traffic. User can specify configuration parameters to shape and control traffic load.
A range of products for traffic generation and network simulation.
