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Cisco Unified IP Phone 7900 Series

Field Notice: FN - 62398 - CP-7911G Will Not Communicate With Network After Firmware Upgrade


May 16, 2006

NOTICE:

THIS FIELD NOTICE IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTY OF MERCHANTABILITY. YOUR USE OF THE INFORMATION ON THE FIELD NOTICE OR MATERIALS LINKED FROM THE FIELD NOTICE IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS FIELD NOTICE AT ANY TIME.


Products Affected

Products Affected

Comments

7911 - CP-7911G

With Boot Load

7911 - CP-7911G-CH1

With Boot Load

Problem Description

In some customer environments, new Cisco Unified IP Phone 7911Gs that were built between December, 2005 and April 15, 2006, might fail to upgrade firmware or hang at Configuring IP in networks with a large layer 2 broadcast domain of 64 or more devices. Sniffer traces will often show that the phone may ignore DHCP responses. This problem does not appear in networks that have been designed within the guidelines provided by the Cisco Solution Reference Network Design (SRND) guides.

Background

New 7911 phones from manufacturing, running firmware release 7.2(0.75), exhibit this problem in large layer 2 broadcast domains of 64 or more devices. The problem does not exist in any 7911 release posted on cisco.com. Only the initial firmware upgrade from early manufactured phones running firmware release 7.2(0.75) is affected.

Problem Symptoms

The CP-7911G hangs at Configuring IP.

In cases where the system administrator has upgraded the Cisco Unified CallManager firmware, and then resets the Cisco Unified IP Phones, the Cisco Unified IP Phone may verify the new load, but will not communicate with the network at layer three.

The phone becomes locked up in reboot mode. The phone may linger with the message Configuring IP and in these cases, the only way to bring the phone back up is to power cycle the phone.

Workaround/Solution

Workaround:

Power cycle the phone. If it still fails to upgrade, move the phone to a smaller network with less than 64 devices in the layer 2 broadcast domain to perform the firmware upgrade. After the firmware is upgraded to version 7.2(1) or higher, the phone can be returned to the large network.

Solution:

Upgrade the boot load.

Amplifying Information:

New Cisco CP-7911G Unified IP Phones built between December, 2005 and April 15, 2006 may fail to upgrade firmware or hang at Configuring IP in networks with a large layer 2 broadcast domain of 64 or more devices. Sniffer traces will often show that the phone ignores DHCP responses.

The problem does not exist in any CP-7911G release posted on cisco.com. Only the initial firmware upgrade from early manufactured phones running firmware release 7.2(0.75) is affected. Power cycle the phone to clear its internal switch CAM. If it still fails to upgrade, move the phone to a smaller network with less than 64 devices in the layer 2 broadcast domain to perform the firmware upgrade.

After the firmware is upgraded to version 7.2(1) or higher, the phone can be returned to the large network. There is no problem with the phone hardware. This is strictly a software anomaly that was erroneously released in the original boot load software image. All Cisco 7911G Unified IP Phones shipped since April 16, 2006 have upgraded boot load images that include a fix for this anomaly. This bug poses no threat to the integrity of the phone hardware.

DDTS

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DDTS

Description

CSCsc59217 (registered customers only)

7911 won't communicate with network after FW upgrade

Revision History

Revision

Date

Comment

1.0

16-MAY-2006

Initial Public Release

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For More Information

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