[62483] in North American Network Operators' Group
Re: .ORG problems this evening
daemon@ATHENA.MIT.EDU (Todd Vierling)
Thu Sep 18 13:13:49 2003
Date: Thu, 18 Sep 2003 13:01:18 -0400 (EDT)
From: Todd Vierling <tv@duh.org>
To: nanog@merit.edu
In-Reply-To: <Pine.LNX.4.44.0309181636040.15418-100000@pop.ict1.everquick.net>
Errors-To: owner-nanog-outgoing@merit.edu
On Thu, 18 Sep 2003, E.B. Dreger wrote:
: TV> Anycasting only works as a redundancy scheme when you have a
: TV> mesh of *partially* overlapping BGP advertisements, so that a
: TV> client has a guarantee that at least one address in the mix
: TV> is located elsewhere from the rest.
:
: Don't be silly. This is like claiming that multihoming only
: works if you spread services over different netblocks.
We're talking about application (DNS) redundancy here, not transport-level
(6to4 anycast RFC comes to mind) redundancy. With this in mind:
: Ergo, that's why one withdraws the routes when a pod dies.
: Routes need to reflect what's up.
BGP doesn't know when a DNS server dies. Therein lies the findamental
problem of using anycast as an application redundancy scheme.
--
-- Todd Vierling <tv@duh.org> <tv@pobox.com>
