Why ICMP is considered such a critical protocol?
Control, troubleshooting and error messages are provided by ICMP that is a protocol within the TCP/IP stack. ICMP is basically a network protocol which is extremely helpful in management and administration of network. It does not carry any application data rather as a control protocol; it carries information on the status of the network. That’s why it is termed as an investigative and error-reporting utility. It needs to be understood that applications don’t use ICMP. Ping and trace router prove helpful to the system administrator in their daily activities and thus are tools to depend on in many conditions. ICMP can not only be used for reporting errors and checking the availability of remote hosts but also for reporting whether the network is overcrowded. Updates and error information to other devices is communicated by ICMP messages. Routers, intermediary devices or hosts use ICMP messages for this purpose.
What is the relationship between IP and ICMP?
Key activities which are always focussed by IP are datagram packaging and routing. Critical support to IP is provided by ICMP in the form of ICMP messages. ICMP defines various types of messages which allow the exchange of various types of information. Now a wide range of error-reporting, feedback and testing capabilities is implemented by the use of ICMP messages.