Patent ID: 7639686

Claim:
A method in a clusterhead of an IPv6 access network, the method including: receiving from an IPv4 host, via one of a plurality of access points providing IPv4 access within the IPv6 access network, a Dynamic Host Configuration Protocol (DHCP) request for assignment of an IPv4 address, the DHCP request within a first IPv6 packet created by the one access point and the first IPv6 packet including an IPv6 address prefix assigned to the one access point and that uniquely identifies the one access point having forwarded the DHCP request; responding by the clusterhead to the DHCP request by assigning to the IPv4 host an IPv4 address that is unique among the access points providing the IPv4 access within the IPv6 access network, including creating a table entry in the clusterhead specifying the IPv4 address is reachable via the IPv6 address prefix of the one access point, and sending a DHCP response to the one access point that specifies the IPv4 address for use by the IPv4 host, wherein any host sending a corresponding DHCP request via one of the access points receives a corresponding unique IPv4 address from the clusterhead; and providing a single access by the clusterhead for any hosts accessing the IPv6 access network via one of the access points, including the IPv4 host, to an IPv4 wide area network, including: (1) receiving from the IPv4 wide area network an IPv4 packet destined for the IPv4 host and having a destination IPv4 address identifying the clusterhead and distinct from the IPv4 address assigned to the IPv4 host, (2) identifying, based on accessing the corresponding table entry in the clusterhead, that the IPv4 host is reachable at the IPv4 address of the IPv4 host via the IPv6 address prefix specified in the table entry, and (3) sending at least a portion of the IPv4 packet to the access point having the corresponding IPv6 address prefix specified in the table entry having been accessed, for delivery to the IPv4 host assigned the IPv4 address, including sending at least the portion of the IPv4 packet in a second IPv6 packet specifying a destination IPv6 address including the IPv6 address prefix specified in the table entry and the IPv4 address assigned to the IPv4 host.