Max Prefixes Configured on Customer BGP (WAS Re: ALGX problems?)

Fri Aug 16 01:00:42 UTC 2002

On Thu, Aug 15, 2002 at 05:15:04PM -0700, Joe Wood wrote:
> 
> However, I don't really see a reason why ISP's shouldn't implement
> max-prefixes on their customer sessions; This would not prevent against
> very small prefix leaks, but would prevent partial and whole routing table
> leaks that impact many networks.

If you're using a Cisco, and they leak, their session stays down until a
human clears it. It also does very little to prevent leaking of a single
route (like one of Phil Rosenthal's /24s), impacting someone else. As a
customer, I would always insist on being prefix-listed and not 
prefix-limited.

I far prefer a prefix list automatically built from IRR entries, with a
NOC and even a website capable of triggering a manual update if you need
to get routes out now. It's all a bit of a hack, but its workable. IMHO AS
Path filters are useless and redundant if you have proper prefix-lists.

-- 
Richard A Steenbergen <ras at e-gerbil.net>       http://www.e-gerbil.net/ras
PGP Key ID: 0x138EA177  (67 29 D7 BC E8 18 3E DA  B2 46 B3 D8 14 36 FE B6)