Internet protocol version six (IPv6) addressing and packet filtering in broadband networks

1. An access node (AN) configured to:

receive an authentication success message associated with a device having a Media Access Control (MAC) address, wherein the device is a residential gateway (RG), wherein the authentication success message is received from an Internet Protocol (IP) edge in a broadband network, and wherein the authentication success message comprises an authentication information that indicates a successful authentication of the device by the IP edge;

snoop the authentication success message to verify the successful authentication of the device by the IP edge;

proxy the device by forwarding a dynamic host configuration protocol (DHCP) prefix request message to the IP edge for IP prefix delegation;

receive and snoop a DHCP reply message to determine an Internet Protocol version 6 (IPv6) prefix assigned to the device, wherein the DHCP reply message is responsive to the DHCP prefix request message;

forward the DHCP reply message to the device, wherein the DHCP reply message comprises an Identity Association for Prefix Delegation (IA_PD) Prefix option comprising the IPv6 prefix and a length of the IPv6 prefix, and wherein the AN received the DHCP reply message from the IP edge prior to forwarding the DHCP reply message to the device;

receive from the device a packet comprising a source MAC address and a source IPv6 address;

drop the packet when the MAC address is equal to the source MAC address and the leftmost bits of the source IPv6 address defined by the length are not equal to the IPv6 prefix; and

maintain a filtering state at the AN, wherein the filtering state comprises an association between the IPv6 prefix and the MAC address.

2. The AN of claim 1 , wherein the MAC address is translated from the device's real MAC address.

3. The AN of claim 1 , wherein the IPv6 prefix allows a host connected to the RG to configure the host's IPv6 address.

4. The AN of claim 1 , wherein the MAC address is associated with a plurality of IPv6 prefixes in a prefix/default router list, and wherein none of the plurality of IPv6 prefixes are equal to the leftmost bits of the source IPv6 address defined by the length.

5. The AN of claim 1 , wherein the source MAC address is derived from a 64-bit extended unique identifier (EUI-64) that is comprised in the source IPv6 address.

6. The AN of claim 1 , wherein the authentication success message is an Extensible Authentication Protocol (EAP) success message that is forwarded to the device by the AN subsequent to snooping of the authentication success message.

7. The AN of claim 1 , wherein the authentication success message comprises: the MAC address of the device, an authentication status that indicates a successful authentication, and a second MAC address corresponding to the IP edge, and

wherein, responsive to receiving the authentication success message, the AN is further configured to:

populate an authentication host list with a first entry corresponding to the MAC address of the device; and

populate a prefix/default router list with a second entry,

wherein the first entry comprises a first pointer that is associated with the second entry, and

wherein the second entry comprises a row consisting of the IPv6 prefix, the length, and the second MAC address.

8. The AN of claim 7 further configured to:

receive an authentication status message from the IP edge device indicating a change to the authentication status of the device; and

update the authentication host list, the prefix/default router list, or both to reflect the change to the authentication status of the device,

wherein the change to the authentication status of the device comprises a revocation of the device's authentication, and

wherein updating the authentication host list, the prefix/default router list, or both to reflect the change to the authentication status of the device comprises deleting the first entry from the authentication host list and the second entry from the prefix/default router list.

9. A computer program product for use by an access node (AN), the computer program product comprising computer executable instructions stored on a non-transitory computer readable medium such that when executed by a processor cause the AN to:

receive an authentication success message associated with a device having a Media Access Control (MAC) address, wherein the device is a residential gateway (RG), wherein the authentication success message is received from an Internet Protocol (IP) edge in a broadband network, and wherein the authentication success message comprises an authentication information that indicates a successful authentication of the device by the IP edge;

snoop the authentication success message to verify the successful authentication of the device by the IP edge;

proxy the device by forwarding a dynamic host configuration protocol (DHCP) prefix request message to the IP edge for IP prefix delegation;

receive and snoop a DHCP reply message to determine an Internet Protocol version 6 (IPv6) prefix assigned to the device, wherein the DHCP reply message is responsive to the DHCP prefix request message;

forward the DHCP reply message to the device, wherein the DHCP reply message comprises an Identity Association for Prefix Delegation (IA_PD) Prefix option comprising the IPv6 prefix and a length of the IPv6 prefix, and wherein the AN received the DHCP reply message from the IP edge prior to forwarding the DHCP reply message to the device;

receive from the device a packet comprising a source MAC address and a source IPv6 address;

drop the packet when the MAC address is equal to the source MAC address and the leftmost bits of the source IPv6 address defined by the length are not equal to the IPv6 prefix; and

maintain a filtering state at the AN, wherein the filtering state comprises an association between the IPv6 prefix and the MAC address.

10. The computer program product of claim 9 , wherein the MAC address is translated from the device's real MAC address.

11. The computer program product of claim 9 , wherein the IPv6 prefix allows a host connected to the RG to configure the host's IPv6 address.

12. The computer program product of claim 9 , wherein the MAC address is associated with a plurality of IPv6 prefixes in a prefix/default router list, and wherein none of the plurality of IPv6 prefixes are equal to the leftmost bits of the source IPv6 address defined by the length.

13. The computer program product of claim 9 , wherein the source MAC address is derived from a 64-bit extended unique identifier (EUI-64) that is comprised in the source IPv6 address.

14. The computer program product of claim 9 , wherein the authentication success message is an Extensible Authentication Protocol (EAP) success message that is forwarded to the device by the AN subsequent to snooping of the authentication success message.

15. The computer program product of claim 9 , wherein the authentication success message comprises: the MAC address of the device, an authentication status that indicates a successful authentication, and a second MAC address corresponding to the IP edge, and

wherein, responsive to receiving the authentication success message, the AN is further configured to:

populate an authentication host list with a first entry corresponding to the MAC address of the device; and

populate a prefix/default router list with a second entry,

wherein the first entry comprises a first pointer that is associated with the second entry, and

wherein the second entry comprises a row consisting of the IPv6 prefix, the length, and the second MAC address.

16. The computer program product of claim 15 , wherein the instructions further cause the AN to:

receive an authentication status message from the IP edge device indicating a change to the authentication status of the device; and

update the authentication host list, the prefix/default router list, or both to reflect the change to the authentication status of the device,

wherein the change to the authentication status of the device comprises a revocation of the device's authentication, and

wherein updating the authentication host list, the prefix/default router list, or both to reflect the change to the authentication status of the device comprises deleting the first entry from the authentication host list and the second entry from the prefix/default router list.