You have two Cisco Unified CallManager clusters each using endpoint authentication. You have moved a small group of users from Cluster 1 to Cluster 2 and now their phones are failing to register with Cluster 2.Each phone displays the error message “failure to authenticate on the CTL file”.Which step should be taken to resolve this issue?
A.
Restart the Cisco CTL Provider and the Cisco Certificate Authority Proxy Function.
B.
Reset each IP phone so the correct CTL file can be downloaded.
C.
Perform a factory reset on each IP phone so the correct CTL file can be downloaded.
D.
Press the Settings button on each IP phone, select the Security Configuration menu, and reset the trust list.