9-8
Cisco Unified IP Phone Administration Guide for Cisco Unified Communications Manager 8.5
OL-23092-01
Chapter 9 Troubleshooting and Maintenance
Troubleshooting Cisco Unified IP Phone Security
Eliminating DNS or Other Connectivity Errors
If the phone continues to reset, follow these steps to eliminate DNS or other connectivity errors:
Procedure
Step 1
Use the
Erase
softkey to reset phone settings to their default values. See
Resetting or Restoring the Cisco
Unified IP Phone, page 9-14
for details.
Step 2
Modify DHCP and IP settings:
a.
Disable DHCP. See
Network Configuration Menu, page 4-5
for instructions.
b.
Assign static IP values to the phone. See
Network Configuration Menu, page 4-5
for instructions.
Use the same default router setting used for other functioning Cisco Unified IP Phones.
c.
Assign TFTP server. See
Network Configuration Menu, page 4-5
for instructions. Use the same
TFTP server used for other functioning Cisco Unified IP Phones.
Step 3
On the Cisco Unified Communications Manager server, verify that the local host files have the correct
Cisco Unified Communications Manager server name mapped to the correct IP address.
Step 4
From Cisco Unified Communications Manager, choose
System > Server
and verify that the server is
referred to by its IP address and not by its DNS name.
Step 5
From Cisco Unified Communications Manager, choose
Device > Phone
and verify that you have
assigned the correct MAC address to this Cisco Unified IP Phone. For information about determining a
MAC address, see
Determining the MAC Address of a Cisco Unified IP Phone, page 2-15
.
Step 6
Power cycle the phone.
Checking Power Connection
In most cases, a phone will restart 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 gets connected to
an external power supply.
Troubleshooting Cisco Unified IP Phone Security
Table 9-1
provides troubleshooting information for the security features on the Cisco Unified IP Phone.
For information relating to the solutions for any of these issues, and for additional troubleshooting
information about security, refer to
Cisco Unified Communications Manager Security Guide
.
Table 9-1
Cisco Unified IP Phone Security Troubleshooting
Problem
Possible Cause
CTL File Problems
Device authentication error.
CTL file does not have a
Cisco Unified Communications Manager
certificate or has an incorrect certificate.
