Field Notice: FN - 64226 - cBR-8-Potential Supervisor Card Reload While Running PCMM Voice and Data Traffic on Cable Modems - Software Upgrade Recommended

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Updated:December 4, 2018

Document ID:FN64226

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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.

Revision History

Revision	Publish Date	Comments
1.0	06-Feb-17	Initial Release
10.0	18-Oct-17	Migration to new field notice system
10.1	03-Dec-18	Fixed Broken Image Links

Products Affected

Affected Product ID	Comments
CBR-CCAP-SUP-160G
CBR-CCAP-SUP-60G

Defect Information

Defect ID	Headline
CSCux40637	SUP crash after running data and pcmm traffic.

Problem Description

The Supervisor (SUP) card might reload due to a memory corruption.

Background

In a SUP card, certain data structures and classes are used for process execution. When a certain class target (downstream dynamic flow) is no longer used, the target class list is not erased properly. This leads to a corruption in the list queue.

This issue can occur under these conditions:

Deletion or reset of all cable modems with the same configuration file (and thus, class parameters)
Shutdown of bundle, Integrated-Cable/Wideband interfaces, or MAC domain
Reset or removal of cBR8 line card

Problem Symptom

The core dump due to this issue can be diagnosed with the GDB (GNU Debugger).

The crash or traceback decode points to a list operation failure due to memory corruption. Cisco Technical Support can decode the IOSD core in order to confirm that this is the root cause.

Check the core file/crashinfo when the SUP protect card is back up and look for Linux-iosd core. An example is shown here:

tb34-cBR8# dir stby-harddisk:core/
Directory of dir stby-harddisk:core/

37 -rw- 1076440910 Oct 25 2016 22:40:03 -04:00 ORLD09-CTS2_RP_1_linux_iosd-imag_16167_1484784055.core.gz
7800705024 bytes total (3328479232 bytes free)

tb34-cBR8#

Workaround/Solution

Cisco highly recommends that customers upgrade to a corresponding release that has the fix as listed in the table in this section.

In the interim, and in order to avoid the SUP issue, it is suggested to not perform any of the three conditions listed in the Background section. If a SUP crash occurs, it is suggested to reload the standby SUP as well.

cBR8 IOS XE Release	Does Issue Exist?	Action
3.15.0S	No	None
3.16.0S	Yes	Upgrade to 3.16.2S or later release
3.16.1S	Yes	Upgrade to 3.16.2S or later release
3.17.0S	Yes	Upgrade to 3.17.1S or later release
3.18.0S	No	None
3.18.0SP or later	No	None

The show version CLI command displays the current software version that runs on the cBR8 router. See this example:

Refer to Upgrading the Cisco cBR-8 Router Firmware for instructions on how to upgrade the cBR-8 Cisco IOS XE Release.

How To Identify Affected Products

The hardware information can be determined as indicated in this picture:

For More Information

If you require further assistance, or if you have any further questions regarding this field notice, please contact the Cisco Systems Technical Assistance Center (TAC) by one of the following methods:

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