Phone Cannot Connect To Lan; Cisco Ip Phone Security Problems; Ctl File Problems; Authentication Error, Phone Cannot Authenticate Ctl File - Cisco 7821 Administration Manual

Phone Cannot Connect to LAN

Problem
The physical connection to the LAN may be broken.
Solution
Verify that the Ethernet connection to which the Cisco IP Phone connects is up. For example, check whether
the particular port or switch to which the phone connects is down and that the switch is not rebooting. Also
ensure that no cable breaks exist.

Cisco IP Phone Security Problems

The following sections provide troubleshooting information for the security features on the Cisco 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 troubleshooting 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.
Solution
Change the security token in the CTL file and install the new file on the phone.
Cisco IP Phone 7821, 7841, and 7861 Administration Guide for Cisco Unified Communications Manager 10.0 (SIP)
Phone Cannot Connect to LAN
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