Open Shortest Path First (OSPF) is an Interior Gateway Protocol (IGP) used to exchange routing information between routers within a single autonomous system (AS).

OSPF calculates the best path based on true costs using a metric assigned by a network administrator.

RIP, the oldest IGP protocol chooses the least-cost path based on hop count.

OSPF is more efficient than RIP, has a quicker convergence, and provides equal-cost multipath routing where packets to a single destination can be sent using more than one interface.

OSPF is suitable for complex networks with a large number of routers. It can coexist with RIP on a network.

You can run OSPF over a route-based VPN by enabling OSPF on a virtual tunnel interface (VTI).

GaiaClosed Check Point security operating system that combines the strengths of both SecurePlatform and IPSO operating systems. supports OSPFv2, which supports IPv4 addressing, and OSPFv3, which supports IPv6 addressing.

To learn about OSPFv3, see IPv6 OSPF.