Patent ID: 7814232

Claim:
A method of providing gateway and NAT services in a redundancy group comprising a first gateway device and a second gateway device, the method comprising: partitioning a pool of unique IP addresses into a plurality of address blocks, including a first address block and a second address block, wherein the first address block contains at least one unique IP address from the pool; assigning the first address block to the first gateway device and the second address block to the second gateway device; in the first gateway device, creating a mapping of a unique IP address in the first address block to a local address of a host serviced by the first gateway device; and notifying the second gateway device of the mapping by sending a communication containing the mapping by the first gateway device to the second gateway device, wherein the first and second gateway devices are configured to perform NAT using the mapping; assigning the host to use the first gateway device to forward a packet from the host destined for a network outside a local network to which the host is coupled; assigning a virtual address to the first gateway device; wherein assigning the host to use the first gateway device comprises instructing the host to send the packet destined for the network outside the local network to the virtual address assigned to the first gateway device; the first gateway device ceasing forwarding of packets from the local network to outside networks; and transferring assignment of the virtual address to the second gateway device.