Which of the following is not a method of deleting an unassigned dn from a UCM database? (Select the best
answer.)

A.
Call Routing > Route Plan Report > Delete

B.
Call Routing > Route Plan Report > Delete Selected

C.
Call Routing > Route Plan Report > Delete All Found Items

D.
Call Routing > Route Plan Report > Delete Unassigned DN

E.
Bulk Administration > Phones > Delete Phones > Delete Unassigned DN

Explanation:
You cannot use Call Routing > Route Plan Report > Delete Unassigned DN to delete an unassigned directory
number (dn) from a Cisco Unified Communications Manager (UCM) database. An unassigned dn is a dn that is
not associated with a specific device, such as an IP phone, but that can still be used to forward calls to voice
mail or to another dn that is associated with a device. For UCM to load and use an unassigned dn, the Active
check box must be selected for the dn. The Active check box is only displayed for unassigned dns.
Problems with unassigned dns can cause an IP phone that is attempting to autoregister with UCM to display the
following error:
Registration Rejected: Error DBConfig
Therefore, you should remove unassigned dns from the autoregistration configuration if this error occurs.
There is no Delete Unassigned DN button in the UCM Call Routing > Route Plan Report window.
You can use Call Routing > Route Plan Report > Delete, Call Routing > Route Plan Report > Delete Selected,
or Call Routing > Route Plan Report > Delete All Found Items to delete an unassigned dn from a UCM
database. If you click a dn that is displayed in the Route Plan Report window and then click the Delete button,
only that dn will be deleted from the UCM database. If you select the check boxes beside a list of dns in the
Route Plan Report window and then click the Delete Selected button, all the dns with selected check boxes will
be deleted from the UCM database. If you click Delete All Found Items in the Route Plan Report window, every
unassigned dn will be deleted from the UCM database, even if the check box beside a dn is not selected.
You can use Bulk Administration > Phones > Delete Phones > Delete Unassigned DN to delete an unassigned
dn from a UCM database. The UCM Bulk Administration > Phones > Delete Phones > Delete Unassigned DN
window automatically searches for and displays a list of unassigned dns in the UCM database. Once the list of
unassigned dns is complete, you should select the Run Immediately radio button and then click Submitto
immediately delete the unassigned dns from the UCM database.

https://www.cisco.com/c/en/us/support/docs/voice-unified-communications/unified-communications-managercallmanager/71440-ccm4x-unassigned-dns.html#maintask1
https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/bat/8_0_2/bat-802-cm/t03delph.html#wp1355300