From: owner-nanog@merit.edu on behalf of Jared Mauch Sent: Sat 9/8/2007 8:17 AM To: William Allen Simpson Cc: nanog@nanog.org Subject: Re: Route table growth and hardware limits...talk to the filter
I think this is the most important point so far. There are a lot of providers that think that their announcements need to be global to manage link/load balancing with their peers/upstreams. Proper use of no-export (or similar) on the more specifics and the aggregate being sent out will reduce the global noise significantly.
Perhaps some of the providers to these networks will nudge them a bit more to use proper techniques.
I'm working on routing leaks this month. There have already been over 2600 leak events today that could have been prevented with as-path filters of some sort, either on a cutomer or peer. (this would obviously be in-addition to prefix-list filters).
- Jared
Maybe this is a dumb question, but why isn't there a BGP option to just filter more specific routes that have the same AS path as the larger aggregate? This would allow the networks that announce more specifics for traffic engineering to still accomplish that, while throwing away the garbage from someone else that decides to announce their /19 as 33 routes for no apparent reason. Sure, this would fail if a network decided to only announce /24's for example without a larger aggregate, but how many networks are really doing that? Forrest