OSPF is a link-state routing protocol. It is designed to be run internal to a single （/） system. Each OSPF router maintains an identical （/） describing the autonomous system's topology. From this database, a routing table is calculated by constructing a shortest-path （ ） . OSPF recalculates routes quickly in the face of topological changes, utilizing a minimum of routing （/） traffic. OSPF provides support for equal-cost multipath. An area routing capability is provided, enabling an additional level of routing protection and a reduction in routing protocol （/）