Ping is a computer network administration software utility used to test the reachability of a host on an Internet Protocol (IP) network and to measure the round-trip time for messages sent from the originating host to a destination computer.
Ping uses ICMP protocol.
Internet Control Message Protocol (ICMP)
Internet Control Message Protocol (ICMP) works at the Network layer and is used by IP for many different services. ICMP is a management protocol and messaging service provider for IP. Its messages are carried as IP datagrams ICMP, which affords host’s extended capability in discovering routes to gateways. ICMP packets have the following characteristics:
They can provide hosts with information about network problems.