Ques : Describe Internet control message protocol

 Internet control message protocol (ICMP) is a network layer protocol. Since Internet Protocol(IP) does not have a built-in mechanism for sending error and control messages, a separate protocol namely: ICMP is used to support error control. It is responsible to report errors and management queries. ICMP is a implemented in the networks devices like routers for sending the error messages and operations information. e.g. host is unreachable. Another use of the ICMP is in congestion control in the network and flow control between sender and receiver by sending a request to decrease traffic rate. ICMP packet is also used in defining the TTL value of a path.