Hi Max, ( and Randy, too, as it hits the same topic ) On Tue, 19 Sep 2006 15:47:51 +0000, Max Tulyev wrote:
It is a good idea to set up the default route to one of upstreams when you set up filtering. This saves routers' memory, but leaves your connectivity fine. You can even accept 0.0.0.0/0 from several upstreams with different localprefs to keep channels back-up working.
This doesn't help the transit provider who is selling upstream to BGP clients. Your default route and Randy's reduced table compete against the full unfiltered table of the other upstream. The more specific prefix _always_ wins.
P.S. I don't believe backbone carriers who don't have upstreams at all need to conserve some extra kilobytes of memory ;)
Ack. In this case there are simply some anti-competitive arguments hidden as resource conservation arguments. Best Regards Oliver Bartels Oliver Bartels F+E + Bartels System GmbH + 85435 Erding, Germany oliver@bartels.de + http://www.bartels.de + Tel. +49-8122-9729-0