Cisco 7821 Administration Manual page 9

Contents
C H A P T E R 1 3
Troubleshooting 175
General Troubleshooting Information
Startup Problems
177
Cisco IP Phone Does Not Go Through Normal Startup Process
Cisco IP Phone Does Not Register with Cisco Unified Communications Manager
Phone Displays Error Messages
Phone Cannot Connect to TFTP Server or to Cisco Unified Communications Manager
178
Phone Cannot Connect to TFTP Server
Phone Cannot Connect to Server
Phone Cannot Connect Using DNS
Cisco Unified Communications Manager and TFTP Services Are Not Running
Configuration File Corruption
Cisco Unified Communications Manager Phone Registration
Cisco IP Phone Cannot Obtain IP Address
Cisco IP Phone Reset Problems
Phone Resets Due to Intermittent Network Outages
Phone Resets Due to DHCP Setting Errors
Phone Resets Due to Incorrect Static IP Address
Phone Resets During Heavy Network Usage
Phone Resets Due to Intentional Reset
Phone Resets Due to DNS or Other Connectivity Issues
Phone Does Not Power Up
Phone Cannot Connect to LAN
Cisco IP Phone Security Problems
CTL File Problems
Authentication Error, Phone Cannot Authenticate CTL File
Phone Cannot Authenticate CTL File
CTL File Authenticates but Other Configuration Files Do Not Authenticate
ITL File Authenticates but Other Configuration Files Do Not Authenticate
TFTP Authorization Fails
Phone Does Not Register
Signed Configuration Files Are Not Requested
802.1X Authentication Problems
Cisco IP Phone 7821, 7841, and 7861 Administration Guide for Cisco Unified Communications Manager 10.0 (SIP)
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