[101635] in North American Network Operators' Group
Re: Asymmetrical routing opinions/debate
daemon@ATHENA.MIT.EDU (Bill Stewart)
Mon Jan 14 20:56:09 2008
Date: Mon, 14 Jan 2008 17:55:12 -0800
From: "Bill Stewart" <nonobvious@gmail.com>
To: "Drew Weaver" <drew.weaver@thenap.com>
Cc: nanog@merit.edu
In-Reply-To: <027301c856c7$14be5e00$be640a0a@CCIEJNCIE>
Errors-To: owner-nanog@merit.edu
There's the somewhat trivial efficiency that if you're willing to
accept asymmetric routing, you spend a lot less time tweaking your
networks than if you insist on symmetry, and the more significant
issue that the network will usually be more resilient and reliable
(though slightly less predictable) if you're not tweaking it.
Essentially, if you don't control all the parts of the network that
your packet uses, you're not able to directly set optimization
parameters, so what you're doing to get symmetry is throwing lots of
hints at the network and hoping some will stick, and the parts of the
network that happen to cooperate with you may not be the best ones
that are otherwise available.
