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Network Protocols Glossary

What is a network protocol? Protocols are the rules of the road for how data exists and moves on the network. They allow many different systems and computers to communicate.

Internet Control Message (ICMP) Protocol

What is Internet Control Message (ICMP) Protocol?

ICMP messages communicate information about network connectivity issues back to the source of the compromised transmission. It sends control messages such as destination network unreachable, source route failed, and source quench. It uses a data packet structure with an 8-byte header and variable-size data section.


What is the purpose of ICMP

ICMP is used by a device, like a router, to communicate with the source of a data packet about transmission issues. For example, if a datagram is not delivered, ICMP might report this back to the host with details to help discern where the transmission went wrong. Ping is an example of ICMP.