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Cisco Unified IP Phone 7906G and 7911G Administration Guide for Cisco Unified CallManager
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Chapter 9 Troubleshooting and Maintenance
Cisco Unified IP Phone Resets Unexpectedly
Eliminating DNS or Other Connectivity Errors
If the phone continues to reset, follow these steps to eliminate DNS or other
connectivity errors:
Step 1 Use the Erase softkey to reset phone settings to their default values. See the
“Resetting or Restoring the Cisco Unified IP Phone” section on page 9-15 for
details.
Step 2 Modify DHCP and IP settings.
a. Disable DHCP. See the “Network Configuration Menu” section on page 4-7
for instructions.
b. Assign static IP values to the phone. See the “Network Configuration Menu”
section on page 4-7 for instructions. Use the same default router setting used
for other functioning Cisco Unified IP Phones.
c. Assign TFTP server. See the “Network Configuration Menu” section on
page 4-7 for instructions. Use the same TFTP server used for other
functioning Cisco Unified IP Phones.
Step 3 On the Cisco Unified CallManager server, verify that the local host files have the
correct Cisco Unified CallManager server name mapped to the correct IP address.
Refer to Configuring The IP Hosts File on a Windows 2000 CallManager Server,
available at this URL:
http://www.cisco.com/warp/customer/788/AVVID/cm_hosts_file.html
Step 4 From Cisco Unified CallManager, 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 CallManager, 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 the “Determining the MAC
Address of a Cisco Unified IP Phone” section on page 2-15.
Step 6 Power cycle the phone.
