[93523] in North American Network Operators' Group
Re: comcast routing issue question
daemon@ATHENA.MIT.EDU (Jordan Hazen)
Thu Nov 30 01:32:56 2006
Date: Thu, 30 Nov 2006 01:23:41 -0500
From: Jordan Hazen <jnh@aug.com>
To: Jim Popovitch <jimpop@yahoo.com>
Cc: nanog <nanog@merit.edu>
In-Reply-To: <1164864510.27888.13.camel@localhost>
Errors-To: owner-nanog@merit.edu
On Thu, Nov 30, 2006 at 12:28:30AM -0500, Jim Popovitch wrote:
>
> On Thu, 2006-11-30 at 00:06 -0500, Jim Popovitch wrote:
> > Question: What could cause the first trace below to succeed, but the
> > second trace to fail?
> >
[snip]
> > Taking the 69.61.40.33/28 subnet a bit further, .36 drops at 68.86.84.70
> > but .37 - .39 make it. .40 drops at 68.86.84.70, but .41 makes it.
> >
> > Crazy.
>
> Btw, the problem has now been resolved, however I'm still curious as to
> what scenario could have caused that.
Perhaps CEF-style load balancing over multiple paths, with one of them
down and not properly failing over? Per-flow balancing would decide
which path to use based on source & target IP.
> -Jim P.
>
--
Jordan.
