A method is disclosed to forward Ethernet frames associated with a service instance at a node (a “forwarding node”) in a network supporting an implementation of a protocol for creating logical loop-free topologies. The method starts with receiving a number of MMRPDUs at the forwarding node from links in the first network (receiving links), where each MMRPDU of the first plurality of MMRPDUs contains a first interested node list including one or more interested nodes identified by MAC addresses. Then a service instance identifier (SID) is identified for the service instance and a first set of MAC addresses interested in the service instance is formed. Then a number of MMRPDUs are sent to links associated with the service instance, where each MMRPDU contains a second set of MAC addresses interested in the service instance. The sending may be accompanied by the node installing filtering at the forwarding node accordingly.