What protocol does ping use?

Ping utilizes the Internet Control Message Protocol (ICMP) to perform its function. When a ping command is issued, ICMP packets are sent from the source device to the target device, prompting the target to respond. This allows the source to determine whether the target is reachable over the network and to measure round-trip time for messages sent. ICMP is specifically designed for error messages and operational queries at the Internet layer, making it the perfect protocol for tools like ping that are used to diagnose network connectivity.

The other protocols listed have different purposes: TCP is a connection-oriented transmission protocol used for reliable data delivery, ARP is used for resolving IP addresses into MAC addresses at the link layer, and UDP is a connectionless protocol that transmits data without establishing a connection, which contrasts with the diagnostic nature of ICMP. This distinction highlights why ICMP is the most appropriate choice for the functionality of the ping command.