US Patent 8149690 Elimination of bad link state advertisement requests

A link-state protocol running on a router requires that an adjacent neighbor router in the same network maintain a synchronized link state database in order to form the adjacency. Should the neighbor request link state information that the router does not possess, normally the adjacency is broken, causing a restart and network instability. The described embodiments allow adjacencies to form and be maintained even when the neighbor makes at least some types of “bad” requests for link state information. Embodiments that operate with and without the knowledge and cooperation of the neighbor are described.