Statically configure route target filtering. Route target filtering allows you to distribute VPN routes to only the routers that need them. In VPN networks without route target filtering configured, BGP distributes all static VPN routes to all of the VPN peer routers. You can add static routes to the bgp.rtarget.0 routing table with specific NLRI-imposed constraints.
A have a VRF - A1 what established eBGP with our upstreamprovider and got 3k routes.
Now I advertise A1'routes to C, D, E via table bgp.l3vpn.0.
The problem is what I wouldn't like B's table bgp.l3.vpn.0 got A1' routes.
How should I do to prevent it ?
On the import policy of the ebgp from A1 add a community value to the routes you learn.
On the export policy from A1 to C, D, E add a first term that matches this community and rejects the route.
Steve Puluka BSEET - Juniper Ambassador IP Architect - DQE Communications Pittsburgh, PA (Metro Ethernet & ISP) http://puluka.com/home