Power Connection Problems; Cisco Unified Ip Phone Security Problems; Ctl File Problems; Authentication Error, Phone Cannot Authenticate Ctl File - Cisco 7941G Administration Manual

Cisco Unified IP Phone Security Problems

Solution
If the phone continues to reset, eliminate DNS or other connectivity errors with
Issues, on page

Power Connection Problems

Problem
The phone does not appear to be powered up.
Solution
In most cases, a phone restarts if it powers up by using external power but loses that connection and switches
to PoE. Similarly, a phone may restart if it powers up by using PoE and then connects to an external power
supply.
Cisco Unified IP Phone Security Problems
The following sections provide troubleshooting information for the security features on the Cisco Unified IP
Phone. For information about the solutions for any of these issues, and for additional troubleshooting
information about security, see Cisco Unified Communications Manager Security Guide.

CTL File Problems

The following sections describe problems with the CTL file:

Authentication Error, Phone Cannot Authenticate CTL File

Problem
A device authentication error occurs.
Cause
CTL file does not have a Cisco Unified Communications Manager certificate or has an incorrect certificate.
Solution
Install a correct certificate.
Phone Cannot Authenticate CTL File
Problem
Phone cannot authenticate the CTL file.
Cause
The security token that signed the updated CTL file does not exist in the CTL file on the phone.
Cisco Unified IP Phone 7941G, 7941G-GE, 7942G, 7961G, 7961G-GE, and 7962G Administration Guide for Cisco
Unified Communications Manager 9.0 (SCCP and SIP)
216
225.
Troubleshooting and Maintenance
Determine DNS or Connectivity