Network

What is ICMP? What is it used for?

Difficulty: unrated

Source: bregman-arie/devops-exercises by Arie Bregman

Answer

  • ICMP stands for Internet Control Message Protocol. It is a protocol used for diagnostic and control purposes in IP networks. It is a part of the Internet Protocol suite, operating at the network layer.

ICMP messages are used for a variety of purposes, including:

  1. Error reporting: ICMP messages are used to report errors that occur in the network, such as a packet that could not be delivered to its destination.
  2. Ping: ICMP is used to send ping messages, which are used to test whether a host or network is reachable and to measure the round-trip time for packets.
  3. Path MTU discovery: ICMP is used to discover the Maximum Transmission Unit (MTU) of a path, which is the largest packet size that can be transmitted without fragmentation.
  4. Traceroute: ICMP is used by the traceroute utility to trace the path that packets take through the network.
  5. Router discovery: ICMP is used to discover the routers in a network.