[161537] in North American Network Operators' Group
routing table go boom (was: Re: [c-nsp] DNS amplification)
daemon@ATHENA.MIT.EDU (Jared Mauch)
Tue Mar 19 14:32:40 2013
From: Jared Mauch <jared@puck.nether.net>
In-Reply-To: <61691C54-2DF8-4AF1-B823-1C4EE746654B@hopcount.ca>
Date: Tue, 19 Mar 2013 14:26:29 -0400
To: Joe Abley <jabley@hopcount.ca>
Cc: "nanog@nanog.org Group" <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Mar 19, 2013, at 2:12 PM, Joe Abley <jabley@hopcount.ca> wrote:
> We've been saying "unconstrained growth bad" for BGP for years. =
Presumably we're not all insane. Where is the science?
I think there is a lot of fear around this topic. I'm waiting to see =
the great meltdown at 512k fib entries in networks. We saw the same at =
128k and 256k with some platforms. The impact on 512k will be just as =
great if not larger, but also very transient. =20
I've observed a great deal of asymmetrical BGP participants in recent =
years. They send a set of routes, sometimes small for their own global =
good, but take only on-net or default routes from their providers.
There is also the fact that many traffic-engineering techniques are =
quite coarse due to the protocol design. The days of using prepending =
and aggregation/deaggregation are still with us, even when more =
sophisticated methods (communities, etc..) exist. I'm starting to =
decide that the real issue is that most people just can't route =
(including some major networks). The system works because the broken =
part gets greased, but there are a lot of cosmetic and non-cosmetic =
defects that linger because people don't realize they are there or are a =
problem. If you want data on that, including my minimalistic "faux" =
science, there is plenty to be had.
- Jared=
