Checking Static Ip Address Settings; Verifying The Voice Vlan Configuration; Verifying That The Phones Have Not Been Intentionally Reset; Eliminating Dns Or Other Connectivity Errors - Cisco 6921 Administration Manual

Chapter 9 Troubleshooting and Maintenance

Checking Static IP Address Settings

If the phone has been assigned a static IP address, verify that you have entered the correct settings. See
the

Verifying the Voice VLAN Configuration

If the Cisco Unified IP Phone appears to reset during heavy network usage (for example, following
extensive web surfing on a computer connected to the same switch as the phone), it is likely that you do
not have a voice VLAN configured.
Isolating the phones on a separate auxiliary VLAN increases the quality of the voice traffic. See the
"Understanding How the Cisco Unified IP Phone Interacts with the VLAN" section on page 2-2
details.

Verifying that the Phones Have Not Been Intentionally Reset

If you are not the only administrator with access to Cisco Unified Communications Manager, you should
verify that no one else has intentionally reset the phones.
You can check whether a Cisco Unified IP Phone received a command from Cisco Unified
Communications Manager to reset by pressing the Applications button on the phone and choosing
Administrator Settings > Status > Network Statistics. If the phone was recently reset, one of these
messages appears:
•
•

Eliminating DNS or Other Connectivity Errors

If the phone continues to reset, follow these steps to eliminate DNS or other connectivity errors:
Procedure
Use the Reset Settings menu to reset phone settings to their default values. See the
Step 1
Restoring the Cisco Unified IP Phone" section on page 9-12
Modify DHCP and IP settings:
Step 2
a.
b.
c.
On the Cisco Unified Communications Manager server, verify that the local host files have the correct
Step 3
Cisco Unified Communications Manager server name mapped to the correct IP address.
Cisco Unified IP Phone 6921, 6941, and 6961 Administration Guide for Cisco Unified Communications Manager 8.0 (SCCP)
OL-20851-01
"Network Setup Menu" section on page 4-4
Reset-Reset—Phone closed due to receiving a Reset/Reset from Cisco Unified Communications
Manager Administration.
Reset-Restart—Phone closed due to receiving a Reset/Restart from Cisco Unified Communications
Manager Administration.
Disable DHCP. See the "Network Setup Menu" section on page 4-4
Assign static IP values to the phone. See the
instructions. Use the same default router setting used for other functioning Cisco Unified IP Phones.
Assign a TFTP server. See the
same TFTP server used for other functioning Cisco Unified IP Phones.
for more information.
"Network Setup Menu" section on page 4-4
"Network Setup Menu" section on page 4-4
Cisco Unified IP Phone Resets Unexpectedly
"Resetting or
for details.
for instructions.
for instructions. Use the
for
for
9-7