Communication protocol | |
Purpose | Auxiliary protocol for IPv4[1]: 52 |
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Developer(s) | DARPA |
Introduction | 1981 |
OSI layer | Network layer |
RFC(s) | RFC 792 |
The Internet Control Message Protocol (ICMP) is a supporting protocol[2] 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.[3] 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).
A separate Internet Control Message Protocol (called ICMPv6) is used with IPv6.[4]
Internet protocol suite |
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Application layer |
Transport layer |
Internet layer |
Link layer |