What protocol is icmp used for?

icmp is the Internet Control Message Protocol. It is a subprotocol of the TCP/IP protocol suite and is used to transmit control messages between IP hosts and routers. Control messages refer to messages about the network itself, such as network connectivity, whether the host is reachable, and whether routes are available.

#The operating environment of this tutorial: Windows 10 system, Dell G3 computer.

What protocol is icmp used for?

ICMP (Internet Control Message Protocol) Internet Control Message Protocol. It is a subprotocol of the TCP/IP protocol suite and is used to transmit control messages between IP hosts and routers. Control messages refer to messages about the network itself, such as network connectivity, whether the host is reachable, and whether routes are available. Although these control messages do not transmit user data, they play an important role in the transmission of user data.

ICMP uses the base support of IP as if it were a higher level protocol, however, ICMP is actually an integral part of IP and must be implemented by every IP module.

Application:

The ICMP protocol is used in many network management commands. The following uses the ping and tracert commands as examples to introduce the application of the ICMP protocol in detail.

(1) The ping command uses ICMP echo request and response messages

The packet internetwork detection command ping used in network reachability testing can generate ICMP echo request and response messages. The destination host immediately sends back a response message after receiving the ICMP echo request message. If the source host can receive the ICMP echo response message, it means that the network reaching the host is normal.

(2) Route analysis diagnostic program tracert uses ICMP time exceeded message

The tracert command is mainly used to display the path that the data packet takes to reach the destination host. By executing a tracert command to the other party's host, the details of the path that the data packet takes to reach the destination host are returned, and the time consumed by each path is displayed.

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