Fabric Shortest Path First (FSPF) is a routing protocol used in Fibre Channel networks. It calculates the best path between switches, establishes routes across the fabric and calculates alternate routes in event of a failure or topology change. FSPF can guarantee in-sequence delivery of frames, even if the routing topology has changed during a failure, by enforcing a 'hold down' time before a new path is activated.
FSPF was created by Brocade Communications Systems in collaboration with Gadzoox, McData, Ancor, and Vixel; it was submitted as an ANSI standard. Introduced around the year 2000, the protocol is similar in conception to the Open Shortest Path First used in IP networks. FSPF has been adopted as the industry standard for routing between Fibre Channel switches within a fabric.
A MIB for FSPF was published as RFC 4626.