Scenario
Refer to the topology. Your company has decided to connect the main office with three other
remote branch offices using point-to-point serial links.
You are required to troubleshoot and resolve OSPF neighbor adjacency issues between the
main office and the routers located in the remote branch offices.

An OSPF neighbor adjacency is not formed between R3 in the main office and R4 in the
Branchl office. What is causing the problem?

A.
There is an area ID mismatch.

B.
There is a Layer 2 issue; an encapsulation mismatch on serial links.

C.
There is an OSPF hello and dead interval mismatch.

D.
The R3 router ID is configured on R4.

Explanation:
A show running-config command on R3 and R4 shows that R4 is incorrectly configured for
area 2: