ICMP is a type of supporting protocol Internet Protocol Suite . They are used by network devices such as Routers, to send error messages and operational information to indicate success and failure, when they communicate with other IP addresses.
The full form of ICMP is ” Internet Control Message Protocol .” When information is transferred over the Internet, computer systems send and receive data using the TCP / IP protocol .
If any problem appears with the connection, then error and status messages are sent to them with reference to that connection through ICMP, which is a part of the Internet protocol.
When a computer is connected to the Internet with another system (such as a home computer is connected to view a website with a web server), it is an easy and quick process.
While this type of connection takes place within a few seconds, there are also many separate connections that need to be made for computers, so that they can communicate successfully among themselves.
In such a situation, if you trace all the steps by an Internet connection, by a traceroute command, then you may be surprised to know that Internet connections are very successful very often. This is because every ” hop ” in that way, the network must be functional in it and also be able to accept requests from your computer.
In cases where there is a problem in connection, ICMP can easily send codes to your system in which they explain why this connection failed.
There may be many messages such as, ” Network unreachable ” for a system that is down, or ” Access denied ” for a secure, password-protected system. ICMP provides routing suggestions in such a way that it helps to bypass unresponsive systems.
Although ICMP has been able to send many different types of messages, but most of them are not visible to the user. If you do not receive an error message, the software you are using, such as a web browser , has already been able to translate that message into easy language (which you can understand and it is less technical ).