There used to be an old flag you could set on an ICMP_ECHO request to record the path the echo reply takes back (ping -R or -r?), but apparently its not used much anymore. Probably just as well.. it could only hold ~8 hops..
 
Andy
----- Original Message -----
From: Darrell Carley
To: nanog@merit.edu
Sent: Thursday, October 17, 2002 10:31 AM
Subject: question concerning traceroute?

I am trying to troubleshoot a latency issue for some of our networks, and was wondering about this…Knowing that routing isn’t always symmetrical, is it possible for a traceroute to traverse a different reverse path, than the path that it took to get there?  …or will it provide a trace of the path the packet took to reach the destination? 

According to definition, is should take the same path, but are there any other cases that I should be aware of?

 

Darrell