Traceroute

Traceroute is a (typically Unix) TCP/IP utility 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.

On Microsoft Windows traceroute is implemented as tracert.

Example

Estonia to the United States. 195.80.96.219 (kauge.aso.ee) to 130.94.122.199 (larousse.wikipedia.org).

1   kauge.aso.ee
2   et-gw.aso.ee
3   kjj-bb2-fe-0-1-4.ee.estpak.ee
4   noe-bb2-ge-0-0-0-1.ee.estpak.ee
5   s-b3-pos0-3.telia.net
6   s-bb1-pos1-2-0.telia.net
7   adm-bb1-pos1-1-0.telia.net
8   adm-b1-pos2-0.telia.net
9   p4-1-2-0.r00.amstnl02.nl.bb.verio.net
10  p4-0-3-0.r01.amstnl02.nl.bb.verio.net
11  p4-0-1-0.r80.nwrknj01.us.bb.verio.net
12  p4-0-3-0.r00.nwrknj01.us.bb.verio.net
13  p16-0-1-1.r20.mlpsca01.us.bb.verio.net
14  xe-1-2-0.r21.mlpsca01.us.bb.verio.net
15  xe-0-2-0.r21.snjsca04.us.bb.verio.net
16  p64-0-0-0.r21.lsanca01.us.bb.verio.net
17  p16-3-0-0.r01.sndgca01.us.bb.verio.net
18  ge-1-2.a03.sndgca01.us.da.verio.net
19  larousse.wikipedia.org