ping
Packet InterNet Groper
ping command
pinging
(ping, originally contrived to match
submariners' term for the sound of a returned sonar pulse) A
program written in 1983 by Mike Muuss (who also wrote TTCP)
used to test reachability of destinations by sending them one,
or repeated, ICMP echo requests and waiting for replies.
Since ping works at the IP level its server-side is often
implemented entirely within the operating system kernel
and is thus the lowest level test of whether a remote host is
alive. Ping will often respond even when higher level,
TCP-based services cannot.
Sadly, Mike Muuss was killed in a road accident on 2000-11-20.
The term is also used as a verb: "Ping host X to see if it is
up."
The Unix command "ping" can be used to do this and to
measure round-trip delays.
The funniest use of "ping" was described in January 1991 by
Steve Hayman on the Usenet group comp.sys.next. He was
trying to isolate a faulty cable segment on a TCP/IP
Ethernet hooked up to a NeXT machine. Using the sound
recording feature on the NeXT, he wrote a script that
repeatedly invoked ping, listened for an echo, and played back
the recording on each returned packet. This caused the
machine to repeat, over and over, "Ping ... ping ... ping ..."
as long as the network was up. He turned the volume to
maximum, ferreted through the building with one ear cocked,
and found a faulty tee connector in no time.
Ping did not stand for "Packet InterNet Groper", Dave Mills
offered this backronym expansion some time later.
See also ACK, ENQ, traceroute, spray.
<The Story of the Ping Program>.
Unix manual page: ping(8).
(2005-06-22)
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