Patent ID: 7688756

Claim:
A provider link state bridging Ethernet node, the node comprising: at least one associated unicast media-access-control (MAC) address; at least one associated multicast MAC address; a routing module for exchanging link state routing information between nodes based upon the respective unicast MAC address and a plurality of multicast MAC addresses of peer nodes and for determining shortest path connectivity between peer nodes and wherein when multiple equal cost paths are available, the selected shortest path is arranged to be consistent for all bridges participating in the routing information exchange; a forwarding information base (FIB) populated with forwarding information received from the routing module for identifying connectivity from the node to peer bridge nodes, wherein the unicast MAC addresses point to peer nodes and the multicast address point from peer nodes; a reverse path forwarding check (RPFC) module for inspecting incoming packets and determining whether the packets arrived on the same ingress port as would be used as an egress port, as determined by the FIB, to forward a packet with a destination MAC address equal to the ingress source MAC address; and a forwarding module for determining, from the FIB, if an egress port of the node is associated with the destination MAC address of a peer bridge and forwarding the packet.