I got an answer for my question.
7018/ATT does ACCEPT /24 routes from 701/mci.
e.g
24.143.13.0/24 on route-server.ip.att.net
has AS-PATH (7018 701 13368).
Is 7018 preferring 19094 over 701 regardless of
AS-PATH length? Or, 7018 will not take prefixes from
other peers if a particular prefix is coming from
19094 regardless of AS-PATH?
** 7018 is just an example. There a quite a few ISP
with the same behavior.
Well .. I'm still in the maze.
Is 7018 preferring 19094 over 701 regardless of
AS-PATH length?
the convention is that, if 19094 is a customer of
7018, then it will always prefer it.
randy
And this is a good reason not to cross "tiers" of your transit providers. Either have both "transit free" or both should have transit.
Is 7018 preferring 19094 over 701 regardless of
AS-PATH length?the convention is that, if 19094 is a customer of
7018, then it will always prefer it.
and it was confirmed that this is the case for the
prefix in question
And this is a good reason not to cross "tiers" of your
transit providers. Either have both "transit free" or
both should have transit.
why? when it get up to tier-1s it will be the same, the
one(s) who heard it from customers will prefer the
customers.
and tier-Ns should be preferring customer routes as well;
see discussion here between vaf, asp, and me in about '96.
randy
slipping back into the tier terminology which i was trying to avoid...
it's only a problem if you want to do inbound traffic engineering. If the tier 2 is well connected to tier 1s (for example Internap), it's typically going to get more inbound traffic than the tier 1 connection because the tier 2 is preferred as a customer in a bunch of tier 1s.