Patent ID: 7113508

Claim:
An apparatus for passing a packet between a local network and a node outside of the local network, the apparatus comprising: means for receiving the packet; means for identifying a first network layer address on the packet that matches a second network layer address in an address translation list specifying combinations of IP addresses of hosts on the local network with globally unique IP addresses from a pool of globally unique IP addresses available for use by the hosts on the local network; means for translating the first network layer address on the packet to a corresponding third network layer address specified in the translation list, wherein a non-globally unique IP address of the host is translated to one of said globally unique IP addresses available from the pool when the packet is sent from the local network and one of said globally unique IP addresses identified as one from the pool is translated to said non-globally unique IP address of the host when the packet is directed to the local network; and means for matching the packet against at least one security criterion.