Bird and aggregates

[Hans van Kranenburg]

Hi,

On 16/04/15 16:43, Joel Brunenberg wrote:
>[...]
>
> So far so good. I would not want to interfere with the Prefixes in the
> OSPF. I however have a BGP-session to another network and I am exporting
> most of my routes to that session. I'd like to replace all the /32
> routes for ptp links with the /24 they are taken from while exporting
> routes for that BGP session.
>
> Since it is totally irrelevant for the peer, which parts of the /24 are
> available, I would just like to attract traffic to the networks I manage
> as long as there are any contributing routes.
>
> [...]
>
> Another idea was a static route for the containing /24 that would be
> exported via BGP while the /32 were filtered away. That however leaves
> the /24 route in place even if there are no more /32 routes left. If
> there is a way to change that, that would be great.

Yes, I would suggest using a static blackhole route with the large 
aggregate range for the BGP connection, and also export that to your 
local kernel routing table to automatically drop traffic for all 
addresses that are currently not in use.

Is there a special reason why you would want to have the /24 being 
removed entirely if none of the other connections is up?

Hans