A mechanism that provides congruent forwarding paths for unicast and multicast data traffic over a service provider core network includes issuing, by a receiver edge node, a request to join a multicast tree structure. A unicast path from the receiver edge node to a source node of the provider network is then established using a special message that contains an identifier. The identifier allows the unicast path through the core network to be aligned with the multicast tree structure. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.