Back Internet Control Message Protocol AN بروتوكول رسائل التحكم في الإنترنت Arabic ICMP Bulgarian Internet Control Message Protocol BS Internet Control Message Protocol Catalan ICMP Czech Internet control message protocol Danish Internet Control Message Protocol German ICMP Greek ICMP EO

Internet Control Message Protocol

This article is about the support protocol for IPv4 (ICMPv4). For ICMPv6, see ICMPv6.
Internet Control Message Protocol
Communication protocol
A general header for ICMPv4
PurposeAuxiliary protocol for IPv4[1]
Developer(s)DARPA
Introduction1981
OSI layerNetwork layer
RFC(s)RFC 792

The Internet Control Message Protocol (ICMP) is a supporting protocol in the Internet protocol suite. It is used by network devices, including routers, to send error messages and operational information indicating success or failure when communicating with another IP address. For example, an error is indicated when a requested service is not available or that a host or router could not be reached.[2] ICMP differs from transport protocols such as TCP and UDP in that it is not typically used to exchange data between systems, nor is it regularly employed by end-user network applications (with the exception of some diagnostic tools like ping and traceroute).

ICMP for IPv4 is defined in RFC 792. A separate ICMPv6, defined by RFC 4443, is used with IPv6.

Internet protocol suite
Application layer
Transport layer
Internet layer
Link layer
  1. ^ F. Baker (June 1995). Baker, F (ed.). Requirements for IP Version 4 Routers. p. 52. RFC 1812.
  2. ^ Forouzan, Behrouz A. (2007). Data Communications And Networking (Fourth ed.). Boston: McGraw-Hill. pp. 621–630. ISBN 978-0-07-296775-3.