Patent ID: 7080157

Claim:
A method for performing overlay routing, comprising: upon receiving a packet at a first router, determining (a) whether the packet contains an overlay header, and (b) whether the packet is to be sent, by the first router, to a destination computer or to a second router; if the packet does not contain an overlay header and the packet is to be sent, by the first router, to the second router, then the first router performing the steps of: (a) generating an overlay header for the packet, wherein the overlay header identifies an overlay address, and (b) routing, to the second router, the packet based on the overlay address, contained in the overlay header, using a first protocol associated with an application layer; if the packet contains an overlay header and the packet is to be sent to the destination computer, then the first router performing the steps of: (a) creating a modified packet by stripping the overlay header off the packet and using the overlay network address identified by the overlay header to determine a network layer address to route the packet to the destination computer, and (b) routing, to the destination computer, the modified packet based on the network layer address using a second protocol associated with a network layer.