Chapter 5, Problem R19RQ

Program Plan Intro

ICMP is Internet Control Message Protocol which is used by the hosts and routers to transfer the network-layer information to each other. One of the usage of ICMP is error reporting.

• ICMP messages consist of three fields.
  • Type – It is a number that uniquely recognizes the type of ICMP message
  • Code – It is a value that gives additional data about the message type.
  • First eight bytes of the IP datagram – To generate an ICMP message.