A link-state protocol that routers use to exchange IP packets over the shortest available end-to-end path based on link-state advertisements from other routers. Router advertisements identify the direction, availability, and cost of links to other routers.With that information, the originating router is able to determine its exit port that leads to the shortest available path to the destination router. OSPF is an Interior Gateway Protocol (IGP) used to exchange path information between routers in the same network domain. See also domain, IGP, IP, link-state protocol, packet, path, port, and router.
(Open Shortest Path First) A routing protocol that determines the best path for routing IP traffic over a TCP/IP network based on distance between nodes and several quality parameters. OSPF is an interior gateway protocol (IGP), which is designed to work within an autonomous system. It is also a link state protocol that provides less router to router update traffic than the RIP protocol (distance vector protocol) that it was designed to replace. See RIP and routing protocol.