On Thu, Oct 17, 2002 at 07:45:39AM -0700, Stephen Stuart wrote: Traceroute sends UDP datagrams and receives ICMP datagrams in order to show you what it shows you. It is possible for the ICMP datagrams to return via a different path than the UDP datagrams took outbound (it is also possible that they will not return). remark it is also possible for the (forward or reverse) path to change in the middle of the measurement, such that traceroute output would lead you to believe a path that never existed anywhere on the Internet (i.e., one that is not manifested in the current physical Internet) and you would not be able to confirm for sure without asking the contacts for the IP links in question how they're connected. traceroute is a disconcertingly blunt hammer; that we continue to use it to essentially nail moving jello to a wall says more about us than about anything on the Internet (and is quite the testimony to van who thought it up and implemented it in a few hours 20 years ago and noone has come up with anything better since.) (caida has a few hundred gigabytes of traceroute-like output on disk, so it's at least auspicious for the mass storage industry if not the jello nailing mission) k
.or will it provide a trace of the path the packet took to reach the destination?
This is not the "or" case of the question you asked previously. Traceroute will display the path that the UDP datagrams took to get to the destination you specified. No information will be presented about the return path that the ICMP datagrams took.
According to definition, is should take the same path
This is not a correct assertion.
but are there any other cases that I should be aware of?
The traceroute man page lists a few. Stephen