Patent ID: 8001269

Claim:
A method of simultaneously providing redundancy gateway services and network address translation (NAT) services using a gateway device in a redundancy group, the gateway device having an active operating mode, wherein the gateway device handles transmissions into and out of a first network only when the gateway device operates in the active operating mode, the method comprising: implementing a NAT functionality in the gateway device for hosts on the first network, wherein the NAT functionality comprises maintaining NAT mappings and implementing an ARP functionality, wherein the NAT mappings map private Internet Protocol (IP) addresses to global IP addresses; disabling the Address Resolution Protocol (ARP) functionality when the gateway device is not in the active operating mode, and wherein implementing the ARP functionality includes responding to ARP requests from external hosts for NAT translated addresses of the hosts on the first network by composing ARP replies and sending the ARP replies; wherein the external hosts are not on the first network and wherein the gateway device is not one of the hosts on the first network.