i want to detect termination of a program in different system..

hi experts,
i wanted to know the IP address of the machine which stopped sending
datagrams.
consider this scenario where 2 or more machines are exchanging
datagrams at regular intervals using raw sockets. when one of the
program crashes for some reason.. the select() is able to detect it
only if it is of type point to point datagram communication.. but if it
is broadcast select() cannot detect it. is there any other solution for
this? how to get an IP address of the machine which has stopped sendin
the datagrams?
also i am storing all the IP's of the machine in a file which are able
to successfully establish a 2 way communication. can it be of any help
in detecting the IP?

pleeze help me..
thankin u in advance
Xoinki