weird BGP cisco-ism? [problem resolved]

You can remove the specifics at the edges of your network either via community
based filtering or prefix based filtering. The former is much more flexible
and is the one I'd recommend.


  I'd think prefix based filters would be more likely to be correct.
Since you have to explicitly list what you think you should be announcing
you protect against having routes you don't expect in your tables and
against having interactions that cause unexpected routes to get tagged as