On 2012-11-15, Daniel Ouellet <dan...@presscom.net> wrote: > On 11/15/12 1:58 AM, Claudio Jeker wrote: >> Why is your router unhappy about this AS path? This is a valid 4-byte >> AS_PATH. Could it be that for some strange reason one side thinks that >> 4-byte AS are enabled and the other still expects 2-byte AS numbers?
Daniel: Specifically, can you check what your router shows for "neighbor capabilities" for the route server in 'sh ip bgp nei'? Anything about "Four-octets ASN Capability"? > But as you can see, it is not that I reject the 4 bytes, I do see them > in the table and I sure process them as well or they would not show up here. Sorry this doesn't prove anything - - the session with your peer can negotiate 4-byte ASN support or not - if it negotiates 4-byte then 4-byte sequences are used in AS_PATH - if it negotiates 2-byte then 2-byte seq's are used in AS_PATH, but there will be an AS4_PATH from the most recent 4-byte speaker that your side will merge with the 2-byte path So you can have 4-byte paths listed in your routing table even though none of your peer sessions have negotiated it.
