ICMP (Internet Control Message Protocol): managing control and diagnostic messages in IP
Fondamental :
IP[1] provides logical addressing and routing, while Ethernet and ARP[2] handle physical delivery within a local network.
However, when sending packets across multiple networks, packets may be lost, a destination may be unreachable, or a route may not exist. To handle these situations, the network needs a protocol to report errors and provide diagnostic information -> ICMP[3] provides this control, it is used for network diagnostics and management.
