1. A network node comprising: a processor configured to: maintain a plurality of mapping entries for one or more virtual network instances; receive a data packet within a first virtual network instance, wherein the data packet comprises an inner destination address; match the inner destination address with one of the mapping entries; obtain an outer destination address that corresponds to the matched mapping entry; encapsulate the data packet with the outer destination address; and forward the encapsulated data packet based on the outer destination address, wherein the mapping entries maps out all of the addresses for a plurality of end nodes that participate in the first virtual network instance.