1. A method of transmitting packets in a computer network having a hierarchy of domains individually having one or more network nodes interconnected with one or more end points, the method comprising: at a network node in a first domain of the hierarchy, receiving a plurality of packets with corresponding end point identifiers individually having a value corresponding to an end point in a second domain different than the first domain; determining at least a portion of a network route from the network node to the end points in the second domain by performing a comparison of at least a portion of the values of the received end point identifiers with entries in a forwarding table in the network node, one of the entries of the forwarding table specifying a higher-level domain corresponding to all end points in the second domain; and forwarding the packets to the higher-level domain based on the determined at least a portion of the network route.