[52814] in North American Network Operators' Group
Re: question concerning traceroute?
daemon@ATHENA.MIT.EDU (alex@yuriev.com)
Thu Oct 17 11:16:36 2002
Date: Thu, 17 Oct 2002 11:21:20 -0400 (EDT)
From: alex@yuriev.com
To: Jared Mauch <jared@puck.Nether.net>
Cc: "Nipper, Arnold" <arnold@nipper.de>,
Darrell Carley <darrell@national-net.com>, nanog@merit.edu
In-Reply-To: <20021017145659.GM17210@puck.nether.net>
Errors-To: owner-nanog-outgoing@merit.edu
> > > > > According to definition, is should take the same path, but are there any
> > > > > other cases that I should be aware of?
> > > >
> > > > According to the definition, it is going to show you the path the packets
> > > > took from you to the destination, not from the destination back.
> > > >
> > >
> > > Unless you did "- g",
> >
> > Not correct. -g specifies loose source routing on the way *there*, not back.
>
> I think the intention was to indicate that you can
> traceroute -g <remote-router-before-host> <your-local-ip>
>
> to get the path to and back. -g requires an argument obviously.
That, obviously, is correct.
However, the remote ip in this case is your local IP, so you are
still getting a path to the destination.
Even more importantly, LSR relies on every router on a forward path
between <your-local-ip> and <remote-router-before-host> allowing LSR, which
is an invalid assumption.
Thanks,
Alex
