Mars
= M =
massage
martian n.
A packet sent on a TCP/IP network with a source
address of the test loopback interface [127.0.0.1]. This means
that it will come back labeled with a source address that is
clearly not of this earth. "The domain server is getting lots of
packets from Mars. Does that gateway have a martian filter?"
Compare Christmas tree packet, Godzillagram.
--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.