Patent ID: 7437470

Claim:
A method for tunneling Internet Protocol Version 6 (IPV6) packets, the method comprising: receiving, by an origin IPv6 border router from an origin IPv6 host, an IPv6 packet having an IPv6 destination address; receiving, by an origin IPv6 border router from an origin IPv6 host, an Internet Protocol Version 4 (IPV4) address for a destination IPv6 border router retrieved from a data structure associating IPv6 destination addresses with IPv4 addresses for destination IPv6 border routers, wherein the data structure associating IPv6 destination addresses with IPv4 addresses for destination IPv6 border routers further comprises a Domain Name System (DNS) resource record that includes the IPv6 destination address for a domain name, and an IPv4 address for a border router capable of receiving an encapsulated lPv6 packet; encapsulating, by the origin IPv6 border router, the IPv6 packet in an IPv4 packet, including adding an IPv4 header to the IPv6 packet; sending the encapsulated packet to a destination IPv6 border router at the IPv4 address; decapsulating, by the destination IPv6 border router, the encapsulated packet, including removing an IPv4 header added by the origin border router from the encapsulated packet; and forwarding, by the destination IPv6 border router, the decapsulated packet to a destination host having the destination IPv6 address.