A (typically UNix) TCP/IP utility which allows the user to determiNe the routepackets 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.