Fibre Channel Addressing and Routing Routing and FSPF
FSPF Functions
F_Port F_Port F_Port F_Port
LSD
Path Selector
Router
Switching Matrix
F_Port
F_Port
F_Port
Switch
F_Port
This diagram illustrates the logical components of the FSPF protocol: • The Link State Database (LSD) contains information about the fabric topology, including all ISLs in the fabric. The LSD is synchronized between all switches in the fabric so that all switches share a common view of the fabric topology.
• The Path Selector is a logical function that determines the most efficient path from a source node to a destination node. The Path Selector uses the information in the LSD to select paths using a cost- based weighting algorithm that takes into account the number of links along each path and the speed of each link.
• The Router routes frames to their destination ports. It utilizes the information from the Path Selector to build its routing table. When an F_Port receives a frame, the Router function looks at the frame’s destination address, looks up the least-cost path, and forwards the frame to the next switch in the selected path—before the switch has even finished receiving the frame.