[c-nsp] 6509 sup 720 + export map

[Oliver Boehmer (oboehmer)]

Tim Franklin <mailto:tim at pelican.org> wrote on Wednesday, November 05,
2008 10:03:

> On Wed, November 5, 2008 6:24 am, Oliver Boehmer (oboehmer) wrote:
> 
>> if I recall correctly, we can't filter/drop routes in VRF export-maps
>> (we can in import-maps).. you could set "no-advertise" or a bogus
>> route-target extcommunity to prevent it from being advertised to your
>> RRs/remote PEs or from being imported into other VRFs.
>> If you don't want to export a certain VRF prefix, just don't
>> redistribute it into BGP (if it's a non-BGP route to begin with).
> 
> Or don't set the export-target that should only be on *some* routes
> in the VRF config, just set on the matching routes in the export-map.


ack, this would work as well.

> I'm
> not sure, off the top of my head, what happens if you have a VRF with
*no*
> export-target defined in the VRF config, but an rt ext-community set
> on some routes in the export map - does the redist from 'local' BGP
into
> MP-BGP still happen? 

yes, and if you don't set an rt-extcomm in the export-map, the prefix is
left without a RT.

> I know there are some gotchas in the other
> direction; even if you're matching an RT in the import map, you still
> need  it as an import target, or the prefix is dropped before it gets
as
> far as the map.

right, this is due to the automatic route-target filter which only
examines the "route-target import" statements in the VRF, not the
route-maps.

	oli