from http://expert.cc.purdue.edu/~frantzen/:

IP Stack Integrity Checker

Its purpose is to test the stability of an IP Stack and its component
stacks (TCP, UDP, ICMP et. al.) It does this be generating random
packets of the desired protocol. The packets can have tendancies. ie
by default all packets have a 50% chance of having IP Options. The
packets are then sent against the target machine to either penetrate
its firewall rules or find bugs in the IP stack.

-d.