[350-401] Difference between FIB and RIB part.1

Question

Which of the following is correct about the difference between RIB and FIB?
  1. FIB creates data based on RIB.
  2. RIB maintains the mirror image of FIB.
  3. The RIB is used to make a switch decision based on the IP source prefix.
  4. All IP routing information is stored in the FIB.

 

See Answer

 

Commentary

FIB(Forwarding Information Base)

FIB is a table that stores transfer information generated when the switching mechanism CEF (Cisco Express Forwarding) is enabled on the device. The FIB contains prefixes from IP routing tables or global RIBs that are structured in a way that is optimized for forwarding. When a routing or topology change occurs in the network, the IP routing table is updated and these changes are reflected in his FIB. The FIB holds the next hop address information based on the information in the IP routing table.

RIB(Routing Information Base)

A central repository for routes containing L3 reachability information and source IP addresses or prefixes. RIB is also known as the routing table.

<reference>https://www.cisco.com/c/ja_jp/td/docs/cian/ios/ios15-1s/cg/013/isw-15-1s-cg/cef-overview.html#16041