hping2 is a network tool able to send custom ICMP/UDP/TCP
packets and to display target replies like ping do with
ICMP replies. hping2 handle fragmentation, arbitrary packet
body and size and can be used in order to transfer files
under supported protocols. Using hping2 you are able at
least to perform the following jobs:

	- Test firewall rules
	- [spoofed] port scanning
	- Test net performance using different protocols,
	  packet size, TOS (type of service) and fragmentation.
	- Path MTU discovery
	- Files transfering even between really fascist firewall rules.
	- Traceroute like under different protocols.
	- Firewalk like usage.
	- Remote OS fingerprint.
	- TCP/IP stack auditing.
	- A lot of others. 

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

-- Roman Shterenzon <roman@xpert.com>