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Re: Networks ignoring prepends?


From: Chris Adams <cma () cmadams net>
Date: Wed, 24 Jan 2024 07:23:34 -0600

Once upon a time, William Herrin <bill () herrin us> said:
On Tue, Jan 23, 2024 at 4:00 PM Chris Adams <cma () cmadams net> wrote:
Once upon a time, William Herrin <bill () herrin us> said:
Nevertheless, in the protocol's design, the one expressed in the
RFC's, AS path length = distance.

The RFC doesn't make any equivalence between AS path length and
distance.  You are the one trying to make that equivalence,

Respectfully Chris, you are mistaken.

https://datatracker.ietf.org/doc/html/rfc4271#section-9.1.2.2

"a) Remove from consideration all routes that are not tied for having
the smallest number of AS numbers present in their AS_PATH
attributes."

So literally, the first thing BGP does when picking the best next hop
is to discard all but the routes with the shortest AS path.

That's literally not the first thing - you skipped section 9.1.1.

It also literally says nothing about distance.

-- 
Chris Adams <cma () cmadams net>


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