[55882] in North American Network Operators' Group
Re: "Selfish Routing"
daemon@ATHENA.MIT.EDU (Stephen Sprunk)
Fri Feb 14 18:20:14 2003
From: "Stephen Sprunk" <stephen@sprunk.org>
To: "Pete Kruckenberg" <pete@kruckenberg.com>
Cc: <nanog@merit.edu>
Date: Fri, 14 Feb 2003 17:15:13 -0600
Errors-To: owner-nanog-outgoing@merit.edu
Thus spake "Pete Kruckenberg" <pete@kruckenberg.com>
> http://www.scienceblog.com/community/article1018.html
> ---
> This might be easier to understand if it was more technical,
> but I'm only aware of a lot of disabled features on my
> routers that are supposed to in theory do some of these
> things.
And they're disabled because they often result in routing loops, usually
transient but sometimes permanent. With very careful planning, you can
create scenarios where these features help; however, it's usually cheaper to
add capacity than to improve efficiency when you include engineering and
operational costs.
> Abstractions and analogies aside, is this really a problem,
> and is it really worth solving? Sounds like a lot of
> additional complexity for the supposed benefits.
Some carriers are solving this problem with MPLS-TE, but not the way the
author suggests.
Other than the MPLS-TE solution, I'm not aware of any ISPs that use
congestion- or RTT-based routing. [E]IGRP is the only IGP with a mechanism
to implement this on a packet level, and experience shows it is unstable in
most topologies.
S
