ICMP
	n There are number of tasks that IP does not perform.  These tasks are done by a helper protocol called: Internet Control Message Protocol (ICMP) n The primary task of ICMP is to report routing errors and anomalies back to the source n ICMP also tests the reachability of a node across the internet n It also provide ways to increase routing efficiency n It also informs the source that a given datagram has exceeded its allocated time