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

Question

Options

• AThe FIB is derived from the data plane, and the RIB is derived from the FIB.
• BThe RIB is a database of routing prefixes, and the FIB is the Information used to choose the
• CFIB is a database of routing prefixes, and the RIB is the information used to choose the egress
• DThe FIB is derived from the control plane, and the RIB is derived from the FIB.
• EThe RIB is derived from the control plane, and the FIB is derived from the RIB.

• A
  6% (4)
• B
  90% (56)
• C
  2% (1)
• D
  2% (1)

Explanation

RIB vs. FIB Explanation

Why B and E are correct: The RIB (Routing Information Base) is a comprehensive database of all known routing prefixes learned from routing protocols, static routes, and connected interfaces - it lives in the control plane. The FIB (Forwarding Information Base) is then derived from the RIB and contains the optimized, pre-computed forwarding entries that the data plane uses to make fast packet-switching decisions, which is exactly what options B and E describe together.

Why the distractors are wrong:

• A is backwards - the FIB comes from the data plane is incorrect; the FIB is actually used by the data plane but derived from the control plane
• C reverses the definitions of RIB and FIB entirely
• D is partially correct about the FIB (control plane) but incorrectly states the RIB is derived from the FIB - it's the opposite direction

Memory Tip: Think of it as a two-step pipeline: RIB → FIB (alphabetical order = processing order). The RIB Receives routing information first, then Forwards it into the FIB for actual packet switching. "Routers Read first, then Forward Fast."

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