Package hping3

TCP/IP stack auditing and much more

http://www.hping.org/

hping3 is a network tool able to send custom TCP/IP packets and to
display target replies like ping do with ICMP replies. hping3 can handle
fragmentation, and almost arbitrary packet size and content, using the
command line interface.
Since version 3, hping implements scripting capabilties

System Administration
Command Description
hping3 send (almost) arbitrary TCP/IP packets to network hosts