On Thu, May 30, 2019 at 10:58 AM Mel Beckman <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 https://bill.herrin.us/