Refer to the exhibit. A network technician is unable to ping from R1 to R2. What will help correct the problem?
A. Ensure that the serial cable is correctly plugged in to the interfaces.
B. Apply the clock rate 56000 configuration command to the serial0/1 interface of R1.
C. Configure the serial0/1 interfaces on R1 and R2 with the no shutdown command.
D. Change the address of the serial0/1 interface of R1 to 192.1.1.4.
E. Change the subnet masks of both interfaces to 255.255.255.240.
I would say A. Protocol down means problem with the cable. Status UP means the interface is not in shutdown mode, but UP. I do not believe that CISCO would allow the clock rate take down the network.
I contradict myself, the answer is B. Sorry!
Answers correct is B, because a interface serial is UP (cable conect ok) line protocol DOWN (is problem in encapsulation or clock rate when is layer two).
Answers correct is B