Sprint BGP filters in 207.x.x.x?

>>If we had a good method for people to indicate routes that they didn't want
to
>>be aggregated, then more proxy aggregation could be done safely.
>>
>
> If I may... The idea of using a routing registry for
> this purpose has been suggested before. I still think
> it is a valid approach. Could be very useful in assisting
> with better proxy aggregation for all.

Let me just say I think the RR has some good uses, i.e.
finding out what people intended the routing to look like, etc.

I don't really understand how a RR can help with proxy aggregation
seeing as the route objects really only provide origin AS
and regular aggregation.

The additional clues can be found in the aut-num for dual homed AS.
If a route is registered with more than one origin AS and you route
differently to these two AS, that's a clue to look carefully before
proxying too.

It seems to me dual homed sites which are the concence of
proxy aggregation, can be detected with a reasonably full set
of routes, i.e. the second from AS from the origin in the ASPATH
being different. (Or some split in the path outside of an
AS communinity or confederation).

The secondary route may not be advertised to you if the primary
suppresses the advertisement. For example if previders are A and B
and they peer with each other, I may think I can aggregate some prefix
over provider A, but B may not be advertising a backup path since it
is preferring the same primary through A.

Curtis