Hi Eric, When non-segmented ingress replication is used, the ingress PE needs to see the Leaf A-D routes from all the egress PEs. (The ingress PE is the upstream parent in this case, even if the ingress PE is not a BGP peer of the egress PEs.) This means that the RT on the Leaf A-D routes needs to identify the ingress PE. However, the Leaf A-D routes may need to travel over multiple BGP sessions before they reach the ingress PE. Some of these BGP sessions may be IBGP sessions, some may be EBGP sessions. It's rather important that the route not get discarded before it reaches the ingress PE, even though it passes through multiple BGP speakers. If one wants to constrain the distribution of the routes, one still has to guarantee that the routes will reach their targets.
[Lucy] If each BGP session keeps track of P-tunnel neighbor state: 1) the downstream neighbor, 2) the upstream neighbor, or 3) N/A. A simple policy can suppress a lot distribution: redistribute a Leaf A-D route if and only if it is sent by a downstream neighbor. This ensures that ingress PE receives all the Leaf A-D routes from all the egress PEs. Thanks, Lucy _______________________________________________ BESS mailing list BESS@ietf.org https://www.ietf.org/mailman/listinfo/bess
