Cisco Unified Ip Phone Cannot Obtain Ip Address; Cisco Unified Ip Phone Displays Security Error Message; Cisco Unified Ip Phone Resets Unexpectedly - Cisco 7975G Troubleshooting And Maintenance

Troubleshooting and Maintenance
To verify that the phone is in the Cisco Unified Communications Manager database, choose Device > Phone >
Find from Cisco Unified Communications Manager Administration to search for the phone based on the
MAC Address. For information about determining a MAC address, see
Determination.
If the phone is already in the Cisco Unified Communications Manager database, its configuration file may be
damaged. See

Cisco Unified IP Phone Cannot Obtain IP Address

Problem
If a phone cannot obtain an IP address when it starts up, the phone may not be on the same network or VLAN
as the DHCP server, or the switch port to which the phone connects may be disabled.
Solution
Ensure that the network or VLAN to which the phone connects has access to the DHCP server, and ensure
that the switch port is enabled.

Cisco Unified IP Phone Displays Security Error Message

Problem
The phone displays "Security Error" on the screen.
Cause
When a Cisco Unified IP Phone boots, it performs an internal Power On Self Test (POST). POST checks for
existing encryption functionality. If POST detects that encryption functionality is missing, the phone fails to
boot, and the message "Security Error" appears on the screen.
Solution
To correct the problem, perform the following steps:
1. Reset the phone manually.
2. If the phone does not start up properly, power up the phone with the handset off-hook. When the phone
is powered up in this way, it attempts to launch a backup software image.
3. If the phone still does not start up properly, perform a factory reset of the phone. For instructions, see
Factory Reset, on page

Cisco Unified IP Phone Resets Unexpectedly

If users report that their phones are resetting during calls or while idle on their desk, you should investigate
the cause. If the network connection and Cisco Unified Communications Manager connection are stable, a
Cisco Unified IP Phone should not reset on its own.
Typically, a phone resets if it has problems connecting to the Ethernet network or to
Cisco Unified Communications Manager. These sections can help you identify the cause of a phone resetting
in your network:
Configuration File Corruption, on page 4
20.
Cisco Unified IP Phone Cannot Obtain IP Address
Cisco Unified IP Phone MAC Address
for assistance.
Troubleshooting and Maintenance
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