on 05.07.2011 14:21 Mikhail A. Grishin wrote:
Matthew Walster wrote, 05.07.2011 16:07:
2011/7/5 Mikhail A. Grishin<magr@ripn.net>:
What purpose of '{' and '}' at BGP.as_path output?
It indicates an "AS Set" - some aggregation happened, the longer routes of which were in the two ASNs in the brackets.
Why at 'show route' we see only '[i]'? (expected to see the first AS in as_path)
IMO, it should show AS48467 as they were the aggregator.
Moreover, this prefix (94.228.160.0/20) was filtered and not accepted because of this BIRD structure: # Apply as_path filters on the last AS (originated route) allas = [ 15905, 34211, 41206, 44116, 44893, 47773, 48467, 50875, 51031, 51186, 51443, 52163 ]; if ! (bgp_path.last ~ allas) then reject;
So bgp_path.last doesn't hit to 48467 in this case. Is this normal?
this is at least the current behaviour. It would be great if bgp_path.last would also be able to operate on an AS-SET. From the top of my head I have no idea how you could do it straight forward. You would have to break up the AS-SET and do the lookup for each AS in the set. Arnold -- Arnold Nipper / nIPper consulting, Sandhausen, Germany email: arnold@nipper.de phone: +49 6224 9259 299 mobile: +49 152 53717690 fax: +49 6224 9259 333