What is the Link-State Database (LSDB) in OSPF?

• A. It is maintained on each router to store link-state information
• B. A database stored in a centralized network server
• C. A table of only direct neighbor routes
• D. A collection of static routes

Answer: (A)

In OSPF, the Link-State Database is a local repository on each router that stores all the link-state information about the area. Routers exchange link-state advertisements describing their own links and reachability, and these LSAs are flooded to all other routers in the area so every router learns about every link. The LSDB contains the complete picture of the area’s topology and is used to run the shortest-path-first algorithm to compute the best paths and populate the routing table. It isn’t stored on a central server, and it isn’t limited to direct neighbor routes or static routes. The content is kept consistent through LSA sequencing and aging, and whenever a link changes, new LSAs update the LSDB across the area. When the network is converged, all routers in the area share the same LSDB content, aside from some differences in special area types like NSSA.