How do the RIB and FIB differ in origin and function?

The Routing Information Base (RIB) is a control plane construct, populated by routing protocols (like OSPF, EIGRP, BGP), static routes, and directly connected networks. It stores all known routes and their associated metrics. The Forwarding Information Base (FIB) is derived from the best routes in the RIB by the control plane. The FIB is optimized for fast lookup by the data plane, containing the necessary information (like next-hop IP and outgoing interface) for efficient packet forwarding. Incorrect options: FIB is built by the control plane; the RIB is built by the data plane: This is incorrect. Both RIB and FIB are built by the control plane. The data plane uses the FIB but does not build it. RIB contains the interface for a destination; FIB contains next-hop information: This is partially true for FIB, but RIB contains much more, including all route attributes, not just the interface. The FIB is a more condensed, forwarding-specific version. FIB contains routes learned via dynamic routing protocols; RIB contains static and directly connected routes: This is incorrect. The RIB contains all types of routes (dynamic, static, connected), and the FIB is a subset of the best routes from the RIB.