traceroute
<networking> A {TCP/IP} utility, originally {Unix}, which
allows the user to determine the {route} {packets} are taking
to a particular {host}. Traceroute works by increasing the
"{time to live}" value of packets and seeing how far they get,
until they reach the given destination; thus, a lengthening
trail of hosts passed through is built up.
(2007-02-02)