Tunneling IPv6 packets

1. A system for tunneling IPv6 packets, the system comprising:

means for receiving, by an origin Internet Protocol Version 6 (IPv6) border router from an origin IPv6 host, an IPv6 packet having an IPv6 destination address;

means for receiving, by an origin IPv6 border router from an origin IPv6 host, an IPv4 address for a destination IPv6 border router retrieved from a data structure associating IPv6 destination addresses with Internet Protocol Version 4 (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 IPv6 packet;

means for encapsulating, by the origin IPv6 border router, the IPv6 packet in an IPv4 packet, including means for adding an IPv4 header to the IPv6 packet;

means for sending the encapsulated packet to a destination IPv6 border router at the IPv4 address;

means for decapsulating, by the destination IPv6 border router, the encapsulated packet, including means for removing an IPv4 header added by the origin border router from the encapsulated packet; and

means for forwarding, by the destination IPv6 border router, the decapsulated packet to a destination host having the destination IPv6 address.

2. The system of claim 1 further comprising;

means for identifying, by the IPv6 host, an IPv6 destination address for the packet; and

means for retrieving, from a data structure associating IPv6 destination addresses with IPv4 addresses for destination IPv6 border routers, an IPv4 address for a destination IPv6 border router;

means for sending an IPv6 packet having the IPv6 destination address to the origin IPv6 border router, and

means for providing to an origin IPv6 border router an IPv4 address for an associated destination IPv6 border router for the IPv6 packet.

3. A computer program product for tunneling Internet Protocol Version 6 (IPv6) packets, the computer program product comprising:

a recording medium;

means, recorded on the recording medium, for receiving, by an origin IPv6 border router from an origin IPv6 host, an IPv6 packet having an IPv6 destination address;

means, recorded on the recording medium, for 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 IPv6 packet;

means, recorded on the recording medium, for encapsulating, by the origin IPv6 border router, the IPv6 packet in an IPv4 packet, including means, recorded on the recording medium, for adding an IPv4 header to the IPv6 packet;

means, recorded on the recording medium, for sending the encapsulated packet to a destination IPv6 border router at the IPv4 address;

means, recorded on the recording medium, for decapsulating, by the destination IPv6 border router, the encapsulated packet, including means, recorded on the recording medium, for removing an IPv4 header added by the origin border router from the encapsulated packet; and

means, recorded on the recording medium, for forwarding, by the destination IPv6 border router, the decapsulated packet to a destination host having the destination IPv6 address.

4. The computer program product of claim 3 further comprising;

means, recorded on the recording medium, for identifying, by the IPv6 host, an IPv6 destination address for the packet; and

means, recorded on the recording medium, for retrieving, from a data structure associating IPv6 destination addresses with IPv4 addresses for destination IPv6 border routers, an IPv4 address for a destination IPv6 border router;

means, recorded on the recording medium, for sending an IPv6 packet having the IPv6 destination address to the origin IPv6 border router; and

means, recorded on the recording medium, for providing to an origin IPv6 border router an IPv4 address for an associated destination IPv6 border router for the IPv6 packet.