Patent ID: 8923296

Claim:
A method of using a controller to control switches in a network having end hosts that are coupled to the switches, wherein the controller is coupled to the switches via network control paths, and wherein the network is coupled to a plurality of gateways that interface between the network and an external network, the method comprising: receiving a network packet, from a given switch based on a flow table entry, that is destined for the external network at the controller, wherein the network packet includes a reserved network address associated with a virtual gateway Internet Protocol (IP) address; with the controller, dynamically selecting a gateway from the plurality of gateways; the controller providing the given switch with the flow table entry that identifies a reserved hardware address; and with the controller, directing the switches to forward the network packet to the external network through the selected gateway, wherein the flow table entry directs the given switch to modify the reserved hardware address in a destination Ethernet address field of the network packet with an Ethernet address of the selected gateway.