consistent policy != consistent announcements
Vince Fuller
vaf at valinor.barrnet.net
Thu Mar 13 19:42:25 UTC 1997
add a peer P to your first example. if P peers with you at
Point1 close to A's connection and again at a Point2 close
to B's connection, then P will hear M's prefixes at Point1
as "R A M" and at Point2 as "R B M". but because the AS
path length is equal, they'll still be able to do closest
exit for M's prefixes.
If that were happening, then we'd consisder the routes to be consistant, at
least for shortest-exit purposes.
What we are seeing, though, is "R A M" at Point1 and nothing at Point2, likely
because Randy doesn't consider "R B M", received from one of his peers, to be
a customer route.
the tone of the "consistent route" policy is to keep one provider from
having to carry packets cross-country in both directions:
Full agreement.
in this example P does not have to do that
In your example, you are correct. But your example doesn't match the situation
that Randy is describing.
--Vince
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