[65199] in North American Network Operators' Group
Re: The Cidr Report
daemon@ATHENA.MIT.EDU (Joe Abley)
Fri Nov 14 14:52:48 2003
In-Reply-To: <9BF6F06C4BC90746ADD6806746492A33690B8C@msmmail01.msmgmt.com>
Cc: <nanog@merit.edu>
From: Joe Abley <jabley@isc.org>
Date: Fri, 14 Nov 2003 14:52:08 -0500
To: "McBurnett, Jim" <jmcburnett@msmgmt.com>
Errors-To: owner-nanog-outgoing@merit.edu
On 14 Nov 2003, at 14:41, McBurnett, Jim wrote:
> just how bad is the auto-summarization at the upstream for the route
> propagation
> via BGP in the large routers anyway?
What auto-summarisation?
If you're talking about the cisco "auto-summary" command, then the
answer is "so bad that it's universally disabled" (but then
"auto-summary" is concerned with aggregation on pre-CIDR, classful
boundaries which I don't think is what you were talking about).
Absent a precise understanding of all the routing policies concerned,
proxy aggregation is dangerous and is hence generally not done.
Joe
