From: Wade Edwards (wade.edwards@xxxxxxxxxxxxxxxxxxx)
Date: Mon Feb 04 2002 - 20:30:34 GMT-3
This is an interesting problem. I assume that the confederation AS_PATH
attributes get stripped off when the route moves to the Adj-RIB-out for
an eBGP peer. But, as I remember, this is when the route-maps,
prefix-lists, filter-lists and distribute-lists are also applied. If
they are not done in the correct order then the AS_PATH attribute will
contain the confederation AS_PATH attributes and the route-map will
filter this route because it does contain AS_PATH information. I am not
sure when the confederation AS_PATH attributes are stripped but it looks
like, at least in the IOS version you have, is being done after the
route-map is being evaluated.
Can you check another version of code and see if this problem persists?
L8r.
-----Original Message-----
From: Libone Mhlanga [mailto:libone@lycos.com]
Sent: Monday, February 04, 2002 3:55 PM
To: ccielab@groupstudy.com
Subject: confeds and the zero length (confed-external) as-path
People,
Halabi says sub-AS's are not counted in calculating the path length,
therefore on his AS border routers he has confgured a filter-list to
allow only locally originated routes ( ie ^$ ).
Problem:- when I try this I find that the border routers will NOT
advertise any routes they have learnt from the other sub-AS eg the bdr
rtr in sub-AS 65060 will not advertise to its EBGP peer any routes
originated in sub-AS 65050 ie the ones with just (65050) in the path.
When I remove the ^$ filter-list it does. So I either have a dodgy level
of IOS 11.2(18) or Halabi's statement is not true.
Any comments ?
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