Targeted neighbor discovery for border gateway protocol

An apparatus, comprising:

• at least one processor;
• and
• at least one memory including instructions that, when executed by the at least one processor, cause the apparatus at least to perform:
• sending, by a first router toward a second router that is multiple network hops away from the first router, a border gateway protocol hello message including an autonomous system number of the first router, a border gateway protocol identifier of the first router, and a set of flags, wherein the set of flags includes a first flag set to a value indicative that the border gateway protocol hello message is a state change hello message, a second flag set to a value indicative that the border gateway protocol hello message is a targeted border gateway protocol hello message, and a third flag set to a value indicative that the first router is requesting that the second router send periodic targeted border gateway protocol hello messages to the first router;
• establishing, by the first router based on the targeted border gateway protocol hello message, a border gateway protocol adjacency between the first router and the second router;
• establishing, by the first router based on the border gateway protocol adjacency, a transport layer connection between the first router and the second router;
• and
• establishing, by the first router based on the transport layer connection, a border gateway protocol session between the first router and the second router.

An apparatus, comprising:

• at least one processor;
• and
• at least one memory including instructions that, when executed by the at least one processor, cause the apparatus at least to perform:
• receiving, at a first router from a second router, a targeted border gateway protocol hello message including a border gateway protocol identifier of the second router and an Internet Protocol address of the second router;
• determining, at the first router based on the border gateway protocol identifier of the second router, that the first router does not have a border gateway protocol adjacency with the second router;
• determining, at the first router, that the Internet Protocol address of the second router is included in a set of target Internet Protocol addresses configured on the first router;
• and
• establishing, by the first router based on the Internet Protocol address of the second router being included in the set of target Internet Protocol addresses configured on the first router, a targeted border gateway protocol adjacency with the second router based on the border gateway protocol identifier of the second router.