Source: https://uptimeify.io/resources/platform-and-support/glossary/icmp-ping

# ICMP / Ping

> ICMP (Internet Control Message Protocol) is the network protocol behind "ping", a simple echo request used to check whether a host is reachable and how long it takes to respond.

A ping monitor sends ICMP echo requests to a server or device and measures reachability, round-trip latency, and packet loss. It is the most basic liveness check for servers, routers, and IoT devices.