Which command must be applied to R2 for an OSPF neighborship to form?

Which command must be applied to R2 for an OSPF neighborship to form?

A . network 20.1.1.2.0.0.0.0 area 0
B. network 20.1.1.2 255.255.0.0. area 0
C. network 20.1.1.2.0.0.255.255 area 0
D. network 20.1.1.2 255.255.255 area 0

View Answer

Answer: A

Explanation:

The network 20.0.0.0 0.0.0.255 area 0 command on R2 did not cover the IP address of Fa1/1 interface of R2 so OSPF did not run on this interface. Therefore we have to use the command network 20.1.1.2 0.0.255.255 area 0 to turn on OSPF on this interface.

Note: The command network 20.1.1.2 0.0.255.255 area 0 can be used too so this answer is also correct but answer C is the best answer here.

The network 0.0.0.0 255.255.255.255 area 0 command on R1 will run OSPF on all active