Highly-available OSPF routing protocol

摘要

In highly-available Open Shortest Path First (OSPF) routing in a network, the dynamic state of a backup OSPF instance 24 in a router is synchronized 222-225 with the dynamic state of an active OSPF instance 23 using explicit message transmission 224 from the active instance to the backup instance. After this, the dynamic state synchronization 225 of the backup OSPF instance 24 is maintained 226 using a combination of explicit message updates from the active OSPF instance together with a message flow-through mechanism. In the event of fail-over 301 of the active OSPF instance 23, then the router 20 recovers seamlessly without reconfiguring or interrupting traffic among peer routers in the network, by functionally substituting 301-310 the synchronized backup OSPF instance 24 for the active OSPF instance 23, such that the backup OSPF instance establishes 301-310 itself as the new active OSPF instance. <IMAGE>