A network packet is encapsulated and has at least one field in the header of the encapsulation. A multicast delivery tree is written into a field of the encapsulating header. A method for operating a router to use the multicast delivery tree encapsulated in the header of the network packet has the following steps. The router receives a packet from a computer network, the packet having an encapsulated field. The router then reads a multicast delivery tree from the encapsulated field, the multicast delivery tree having a route to each of a plurality of destination stations. Then, the router forwards the packet to an address selected in response to the multicast delivery tree.