A network administrator uses autoregistration to register IP phones to Cisco Unified
Communications Manager. Later, the administrator changes the DN of the autoregistered phone to
free the DN in the autoregisteration range. After a certain amount of time, the phones fail to
autoregister, displaying “Error DB Config” or a similar message on the IP Phone screen. What is
the root cause of this issue?

A.
The network is down.

B.
Cisco Unified Communications Manager server is down.

C.
The phone is faulty.

D.
The DNs are marked as unassigned.

Explanation: