Eliminating Dns Or Other Connectivity Errors; Checking Power Connection - Cisco IP Phone Administration Manual

Cisco Unified IP Phone Resets Unexpectedly
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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 Erase softkey to reset phone settings to their default values. See
Step 1
Unified IP Phones, page 9-13
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.
From Cisco Unified Communications Manager, choose System > Server and verify that the server is
Step 4
referred to by its IP address and not by its DNS name.
From Cisco Unified Communications Manager, choose Device > Phone > Find and verify that you have
Step 5
assigned the correct MAC address to this Cisco Unified IP Phone. For information about determining a
MAC address, see
Power cycle the phone.
Step 6

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 Power over Ethernet (PoE). Similarly, a phone may restart if it powers up by using PoE and
then gets connected to an external power supply.
Cisco Unified IP Phone Administration Guide for Cisco Unified Communications Manager 8.6 (SCCP and SIP)
9-8
Reset-Restart—Phone received a Reset/Restart request from Cisco Unified Communications
Manager Administration.
Disable DHCP. See Network Configuration Menu, page 4-5
Assign static IP values to the phone. See
Use the same default router setting used for other functioning Cisco Unified IP Phones.
Assign a TFTP server. See
TFTP server used for other functioning Cisco Unified IP Phones.
Determining the MAC Address for a Cisco Unified IP Phones, page
for details.
Network Configuration Menu, page 4-5
Network Configuration Menu, page 4-5
Chapter 9 Troubleshooting and Maintenance
Resetting or Restoring the Cisco
for instructions.
for instructions.
for instructions. Use the same
2-13.
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