An internet protocol (IP) traffic control method comprising receiving a message that comprises multicast group information and distribution tree root information from a tree root node in a first network area, determining the border network node is a designated forwarder for the second network area, sending an announcement message that comprises the multicast group information and the distribution tree root information within the second network area, receiving multicast group membership information for a multicast group computing a multicast group membership summary for the first network area and the second network area, sending the multicast group membership summary to first network area and the second network area, computing a distribution tree using the multicast group information and the distribution tree root information, pruning the distribution tree to generate a multicast tree, and communicating multicast data traffic between the first network area and the second network area along the multicast tree.