nanog mailing list archives
Re: BGP prefix filter list
From: Mel Beckman <mel () beckman org>
Date: Thu, 30 May 2019 20:00:54 +0000
Yes, my original quote wasn’t exactly word-for-word from the standard, but it was semantically identical. I’m sure we can find corner cases, but it’s clear that the vast majority of BGP users are following the standard. Anycast isn’t a violation of the standards because it’s defined in BGP as a single destination address having multiple routing paths to two or more endpoints. -mel On May 30, 2019, at 12:48 PM, William Herrin <bill () herrin us<mailto:bill () herrin us>> wrote:
On Thu, May 30, 2019 at 10:58 AM Mel Beckman <mel () beckman org<mailto:mel () beckman org>> wrote:Come on now. The definition of an autonomous system is well established in RFC1930, which is still Best Current Practice: https://tools.ietf.org/html/rfc1930#section-3
Your quote wasn't from the RFC. Sorry, my google fu is only good enough to find your actual quote, not the similar one you didn't reference.
An AS is a connected group of one or more IP prefixes run by one or more network operators which has a SINGLE and CLEARLY DEFINED routing policy.
Interesting but it bears little resemblance to modern practice. Consider an anycast announcement, for example, where multiple distributed servers at isolated pops terminate the packet. Consider Amazon where both region-local unicast announcements and global anycast announcements all originate from AS 16509. Indeed the whole concept of traffic engineering rests on the premise that an AS' routing policy is NOT the same at every border. Regsards, Bill Herrin -- William Herrin bill () herrin us<mailto:bill () herrin us> https://bill.herrin.us/
Current thread:
- Re: BGP prefix filter list, (continued)
- Re: BGP prefix filter list William Herrin (May 24)
- Re: BGP prefix filter list Blake Hudson (May 24)
- Re: BGP prefix filter list William Herrin (May 24)
- Re: BGP prefix filter list James Jun (May 25)
- Re: BGP prefix filter list Robert Blayzor (May 30)
- Re: BGP prefix filter list William Herrin (May 30)
- Re: BGP prefix filter list Mel Beckman (May 30)
- Re: BGP prefix filter list William Herrin (May 30)
- Re: BGP prefix filter list Mel Beckman (May 30)
- Re: BGP prefix filter list William Herrin (May 30)
- Re: BGP prefix filter list Mel Beckman (May 30)
- Re: BGP prefix filter list Thomas Bellman (May 30)
- Re: BGP prefix filter list Mel Beckman (May 30)
- Re: BGP prefix filter list Valdis Klētnieks (May 30)
- Re: BGP prefix filter list Mel Beckman (May 30)
- Re: BGP prefix filter list Thomas Bellman (May 31)
- Re: BGP prefix filter list Valdis Klētnieks (May 30)
- Re: BGP prefix filter list Matt Corallo (May 30)
- Re: BGP prefix filter list Saku Ytti (May 30)
- Re: BGP prefix filter list Robert Blayzor (May 30)
- Re: BGP prefix filter list William Herrin (May 30)