Exam 200-301 topic 1 question 159 discussion

The data plane forwards traffic flows. The data plane is the forwarding plane, which is responsible for the switching of packets through the router.

forwarding information base (FIB) is including look up egress interface for find the best path that is why both C and B are related to data plan but B is the more comprehensive answer. B is correct

B and C are both within data plane. FIB is built by the control plane, but utilised by the data plane. It is the data plane that looks up the destination in the FIB. This question is faulty.

B is correct

I choose D, for C, since CEF consists of FIB and Adjacency Tables. FIB is structured as a tree of 4 layers, and each layer has node from 0-255(destination address quick look up). At each leaf node, it has a pointer to the Adjacency table. CEF uses the Adjacency table to prepend Layer 2 addressing information. The adjacency table maintains Layer 2 next-hop addresses for all FIB entries. So, it looks for the adj table for egress interface not FIB

Option 'b' is correct. By definition, (official cert guide) "The term data plane refers to the tasks that a networking device does to forward a message". Further, not all devices may have a FIB, so that can rule out option 'c'.

B and C are all correct.

believe better answer

i believe correct answer is C. Looks up an egress interface in the forwarding information base. Question mentioned "data plane", not control plane, so control plane determine first: Next hop then output interface, so "data plane must only get to the egress interface (and there is no need for going to another network it will happens if the network device relates to the same segment). Makes more sense for me.

Poorly written question, but B would be the answer

B is correct

B is correct.