[c-nsp] Configure two AS on one BGP router

[Saku Ytti]

On (2007-07-03 21:54 +0200), Philippe Strauss wrote:
 
> I recall seeing a new feature, if my memory serves well in 12.4, named
> something like BGP AS migration. Don't know if it does fit your purpose,
> never used it myself.

 It appears as either AS# to your peers. e.g. your customer can
change the 'remote-as' at their convenience, without needing
to synchronize the change with you. You can opt not to prepend,
so that you'll always just see your real-AS customer-AS in 
AS-path, not the 'local-as' even if the customer is actually
peering with it. Same goes other way, you can opt so that
customer sees prefixes coming just from the AS# they peer with,
not the local-as + real-as. e.g. you can do migration, without
increasing AS path length to either side at any point.
 This mostly makes sense, if you have quite large bunch of 
customers, and only makes sense in migration, same with local-as.
I would dearly recommend the original poster to just go ahead 
and do full migration in rather rapid way to a single AS, I foresee
quite bit of headache from the setup otherwise.

Thanks,
-- 
  ++ytti