Setting a forwarding address in an internet protocol version 6 (IPv6) routing protocol domain at a boundary with a different routing protocol domain

An apparatus comprising:

• means for receiving a neighbor discovery message through an interface to a border network segment between a first plurality of nodes for routing with Internet Protocol (IP) version 6 (IPv6) using a first routing protocol and a different second plurality of nodes for routing using a different second routing protocol, wherein the apparatus is among the first plurality of nodes and the neighbor discovery message is received from an alien router among the second plurality of nodes, wherein the first routing protocol comprises an Enhanced Interior Gateway Router Protocol (EIGRP) configured to set a forwarding address (FA) field in advertisement messaging associated with external routes involving a particular router, and wherein the alien router and the particular router communicate level 3 summarized routing information using an External Border Gateway Protocol (EBGP);
• means for receiving, from the alien router through the interface, a border routing message that includes foreign routing data that indicates a route to a destination in the second plurality of nodes;
• means for determining whether the alien router has a global IP address, wherein the particular router includes a forward alien address process configured to forward an address for the alien router when the alien router does not have the global IP address;
• and
• means for substituting a fictive address, if it is determined that the alien router does not have a global IPv6 address, comprising
• means for generating a fictive IPv6 address that includes data that indicates a global prefix of an IPv6 address for the particular router and an interface identifier (ID) associated with the alien router;
• means for inserting the fictive IPv6 address and the foreign routing data into a domain scope external advertisement message;
• means for sending the advertisement message to the first plurality of nodes;
• means for receiving a neighbor solicitation message that indicates a request to resolve a MAC identifier for the fictive IPv6 address;
• and
• means for sending a neighbor advertisement message that includes data that identifies the MAC identifier for the interface on the alien router.

An apparatus comprising:

• a first network interface that is configured to communicate a data packet with a first packet-switched network of a first plurality of nodes that are routing with Internet Protocol (IP) version 6 (IPv6) using a first routing protocol;
• a second network interface that is configured to communicate a data packet with a border network segment that is in communication with a different second plurality of nodes that are routing using a different second routing protocol;
• and
• logic encoded on a non-transitory tangible media for execution by a processor and, when executed by a processor, operable to perform the steps of:
• receiving a neighbor discovery message through the second network interface from a different, alien router on the border network segment, wherein the first routing protocol comprises an Enhanced Interior Gateway Router Protocol (EIGRP) configured to set a forwarding address (FA) field in advertisement messaging associated with external routes involving a particular router, and wherein the alien router and the particular router communicate level 3 summarized routing information using an External Border Gateway Protocol (EBGP);
• receiving, from the alien router through the second network interface, a border routing message that includes foreign routing data that indicates a route to a destination in the second plurality of nodes;
• determining whether an interface on the alien router to the border network segment has a global IP address, wherein the particular router includes a forward alien address process configured to forward an address for the alien router when the alien router does not have the global IP address;
• and
• if it is determined that the interface on the alien router does not have a global IP address, then performing the steps of:
• generating a fictive IPv6 address that includes data that indicates a global prefix of an IPv6 address for the apparatus and an interface identifier (ID) associated with the alien router;
• inserting the fictive IPv6 address and the foreign routing data into a domain scope external advertisement message;
• sending the external advertisement message through the first network interface to the first plurality of nodes;
• receiving a neighbor solicitation message that indicates a request to resolve a MAC identifier for the fictive IPv6 address;
• and
• sending a neighbor advertisement message that includes data that identifies the MAC identifier for the interface on the alien router.