Shortest Path First (SPF) based routing protocols are a class of link-state algorithms that are based on the shortest-path algorithm of Dijkstra. Although SPF based algorithms have been around since the inception of the ARPANET, it is only recently that they have achieved popularity both inside both the IP and the OSI communities. In an SPF based system, each router obtains the entire topology database through a process known as flooding. Flooding insures a reliable transfer of the information. Each router then runs the SPF algorithm on its database to build the IP routing table. The OSPF routing protocol is an implementation of an SPF algorithm. The current version, OSPF version 2, is specified in [ROUTE:1]. Note that RFC-1131, which describes OSPF version 1, is obsolete.
Note that to comply with Section [8.3] of this memo, a router that implements OSPF MUST implement the OSPF MIB [MGT:14].