Software → Computer Networks
Internet Control Message Protocol
A network-layer protocol used for diagnostics and control messages such as ping errors.
Motivation
ICMP solves the problem of reporting network control and diagnostic information.
Where it fits
ICMP belongs to computer networks and is best known through tools such as ping and traceroute.
Mental model
ICMP is not for application data; it is for network messages about reachability, errors, and diagnostics.
Common mistakes
- Thinking ICMP is the same as TCP or UDP.
- Blocking all ICMP without considering operational diagnostics.
Related concepts
ICMP connects to IP, routing, packet, and network troubleshooting.