System and method for mapping an index into an IPv6 address

A method for use by an intermediate network device having a plurality of interfaces for forwarding network packets among the interfaces, one or more of the interfaces being associated with one or more Virtual Local Area Network (VLAN) designations, the method comprising the steps of:

• mapping, by a routing processor, each VLAN designation to an Internet Protocol version 6 (IPv6) site identifier in a table;
• receiving on an inbound interface a packet having an IPv6 site-local unicast destination address in a field of a header;
• identifying the VLAN designation associated with the received packet;
• utilizing the identified VLAN designation to retrieve the IPv6 site identifier to which the VLAN designation is mapped;
• and
• creating a modified destination address by embedding the retrieved IPv6 site identifier into the IPv6 site-local unicast destination address.

An intermediate network device for forwarding packets within a computer network, the device comprising:

• a plurality of interfaces for receiving and forwarding packets, one or more of the interfaces associated with one or more virtual local area network (VLAN) designations;
• a forwarding information base (FIB) for storing routing information;
• a routing engine in communicating relationship with the FIB, the routing engine configured to make forwarding decisions for received packets, based at least in part on the routing information in the FIB;
• and
• a memory in communicating relationship with the routing engine, the memory configured to store the VLAN designations associated with the device's interfaces in mapping relationship with one or more Internet Protocol version 6 (IPv6) site identifiers,
• wherein the routing engine identifies the VLAN designation associated with the received packet, utilizes the identified VLAN designation to retrieve the IPv6 site identifier to which the VLAN designation is mapped, and creates a modified destination ad-dress by embedding the retrieved IPv6 site identifier into an IPv6 site-local unicast destination address, and
• wherein the routing engine utilizes the memory to ensure that a packet having an IPv6 site-local unicast source and/or destination address is only forwarded between inter-faces corresponding to the same IPv6 site identifier.

A method for use by an intermediate network device having a plurality of interfaces for forwarding network packets among the interfaces, one or more of the interfaces being associated with one or more Virtual Local Area Network (VLAN) designations, the method comprising the steps of:

• receiving on an inbound interface a packet having an Internet Protocol version 6 (IPv6) link-local unicast destination address in a field of a header;
• identifying the VLAN designation associated with the received packet;
• creating a modified destination address by embedding the identified VLAN designation into the IPv6 link-local unicast destination address;
• and
• rendering a forwarding decision for the received packet based on the modified destination address.

An intermediate network device for forwarding packets within a computer network, the intermediate device comprising:

• means for mapping, by a routing processor, one or more VLAN designations to an Internet Protocol version 6 (IPv6) site identifier in a table;
• means for receiving a packet having an IPv6 site-local unicast destination address in a field of a header;
• means for identifying a particular VLAN designation associated with the received packet;
• means for retrieving the IPv6 site identifier to which the particular VLAN designation is mapped;
• means for creating a modified destination address by embedding the retrieved IPv6 site identifier into the IPv6 site-local unicast destination address;
• and
• means for rendering a forwarding decision for the received packet based on the modified destination address.

A computer readable medium containing computer-executable program instructions for forwarding packets within a computer network, the computer-executable program instructions comprising computer-executable program instructions configured to:

• map, by a routing processor, one or more VLAN designations to an Internet Protocol version 6 (IPv6) site identifier in a table;
• identify a particular VLAN designation associated with a received packet that has an IPv6 site-local unicast destination address in a field of a header;
• retrieve the IPv6 site identifier to which the particular VLAN designation is mapped;
• create a modified destination address by embedding the retrieved IPv6 site identifier into the IPv6 site-local unicast destination address;
• and
• render a forwarding decision for the received packet based on the modified destination address.

An apparatus comprising:

• a plurality of interfaces configured to receive and forward packets, one or more of the interfaces associated with one or more virtual local area network (VLAN) designations;
• a forwarding information base (FIB) configured to store routing information;
• a routing engine in communicating relationship with the FIB, the routing engine configured to make forwarding decisions for received packets, based at least in part on the routing information in the FIB;
• and
• a memory in communicating relationship with the routing engine, the memory configured to store the VLAN designations associated with the device's interfaces in mapping relationship with one or more Internet Protocol version 6 (IPv6) site identifiers,
• wherein the routing engine is further configured to, in response to receipt of a packet on an inbound interface having an IPv6 site-local unicast destination address in a field of a header, identify a VLAN designation associated with an outbound interface from which the packet is to be forwarded, utilize the identified VLAN designation for the outbound interface to retrieve an IPv6 site identifier to which the VLAN designation is mapped, creating a modified destination address by embedding the retrieved IPv6 site identifier into the IPv6 site-local unicast destination address, compare an IPv6 site identifier associated with an inbound interface with the IPv6 site identifier associated with the outbound interface, and if the two IPv6 site identifiers match, forward the packet on the outbound interface, and if the two IPv6 site identifiers do not match, drop the packet without forwarding.