Implementing and Operating Cisco Enterprise Network Core Technologies (ENCOR) — Question 140

What are two differences between the RIB and the FIB? (Choose two.)

Answer options

• A. FIB is a database of routing prefixes, and the RIB is the information used to choose the egress interface for each packet.
• B. The FIB is derived from the data plane, and the RIB is derived from the FIB.
• C. The RIB is a database of routing prefixes, and the FIB is the information used to choose the egress interface for each packet.
• D. The RIB is derived from the control plane, and the FIB is derived from the RIB.
• E. The FIB is derived from the control plane, and the RIB is derived from the FIB.

Correct answer: C, D

Explanation

Option C is correct because the RIB indeed contains routing prefixes, while the FIB holds information to determine the egress interface. Option D is also correct since the RIB is constructed from control plane information, whereas the FIB is based on the RIB. The other options incorrectly describe the relationships and functions of RIB and FIB.