Ping

`ping` is a software utility used to test the reach-ability of hosts. It is available for virtually all operating systems, including most embedded network administration software.

Ping measures the round-trip time for messages sent from the originating host to a destination computer that are echoed back to the source. The name comes from active sonar terminology that sends a pulse of sound and listens for the echo to detect objects under water. The program reports errors, packet loss, and a summary of the results, typically with the minimum, maximum, the mean round-trip times.