Patent ID: 8913485

Claim:
A method of operation of a network element for open shortest path first (OSPF) non-stop routing, wherein the network element comprises a first OSPF instance currently acting as an active OSPF instance and a second OSPF instance currently acting as a standby OSPF instance, the method comprising: attempting to create a FULL adjacency with a neighbor network element using a neighbor state machine of the active OSPF instance, the step of attempting comprising: maintaining a neighbor data structure for the neighbor network element prior to the neighbor state machine transitioning to or from a full state; installing link state advertisements (LSAs) received from the neighbor network element in both a link state database (LSDB) of the active OSPF instance and the standby OSPF instance; and if and when the neighbor state machine of the active OSPF instance transitions to the full state and if a switch causes the second OSPF instance to act as the active OSPF instance, retrieving virtual neighbor information from the LSAs of the second OSPF instance and deriving a virtual link between the network element and the neighbor network element based on the retrieved virtual neighbor information in order to create the FULL adjacency with the neighbor network element, and wherein the virtual link between the network element and the neighbor network element is derived without synchronizing the virtual neighbor information between the first OSPF instance and the second OSPF instance.