ICMP (Internet Control Message Protocol) is a network layer protocol used to send error messages and other control information between network devices. ICMP is an essential protocol for network troubleshooting and diagnostics. It is commonly used to check if a network device is reachable and to identify the source of network problems.
There are several ways to check if ICMP is blocked. One common method is to use the ping command. The ping command sends ICMP echo request messages to a specified destination and waits for ICMP echo reply messages in return. If ICMP is blocked, the ping command will not be able to send or receive ICMP messages, and it will report an error.
