Field Notice: FN - 63048 - MGX-RPM-XF-512 SAR Memory Corruption - Replace on Failure

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

Products Affected

Defect Information

Problem Description

MGX-RPM-XF-512 boards shipped after Dec 1, 2006 use a specific version of SRAM which may be affected by power supply noise. This can cause the SAR Controller internal memory register to corrupt and cause a board crash.

Background

All version (TAN) 800-09307-08 boards shipped after Dec 1, 2006 are subject to this condition.

The version number (TAN) 800-09307-09, was released on Oct 23, 2007 but boards were not built or shipped to customers.

After 2/19/2008, Boards built under TAN 800-09307-10 are not subject to this condition.

Problem Symptom

Between mid 2007 and early 2008, Cisco MGX Customers experienced intermittent failures on MGX-RPM-XF-512 boards.

This resulted in both SAR reset and occasional board reset issues during normal operation. These failures are soft in nature and the board will function normally after reset.

Either the SAR reset or board reset will cause a traffic impacting event. Each time a board resets, the system log will show an interrupt received from the segmentation SAR.

The error will also be present in a crash file named "sar_mxt4600_tx_info" as shown below. The crash file is stored in bootflash memory.

An example of a SAR crash message from the crash file:

SWITCH_IF-3-INTERRUPT: Received interrupt from SEGMENTATION SAR - OCTRAP register = 0x000004BD

In some events the SAR crashinfo file written to the bootflash could be incomplete. It may be viewed using the "show bootflash:" command. The cyclic redundancy check (crc) of the incomplete file will be shown as 0xFFFFFFFF in the example below:

2 E. unknown FFFFFFFF 4ABB9C 35 108520 Jun 25 2007 16:58:33 +00:00 sar_mxt4600_tx_info_20070625-165833

Another symptom that may be observed is SAR buffer exhaustion. The command "show controller Switch1", shows the SAR buffer usage in class 2 buffers for Segmentation SAR greater than 100%

Workaround/Solution

Cisco has proactively replaced all suspect boards in customer network. The proactive replacement program for this issue is closed. Cisco recommends replacement of suspect board with help of table below. Follow the Cisco RMA Procedure to request replacement, and enter failure code as "Field Notice Alert" and refer to this FN number.

As of approximately February 19th, 2008 new products that were manufactured under Engineering Change Order (ECO) E092444 are guaranteed to be free of this problem. Parts remanufactured under this ECO will be upgraded to Ver -10.

Refer to "How to Identify Affected Products" for instructions on how to view the version of in-service product. Matching serial numbers that are remanufactured to Version -10 are free of this defect and do not need to be replaced.

Note: 800-09307-09 was not shipped to Customer

For failure observered related to this Field Notice, follow the Cisco RMA Procedure.

How To Identify Affected Products

A) Command Line Interface (CLI) to Identify Serial Number and TAN

This example shows a suspected board.

Note: The boards with matching serial numbers and part number 800-09307-10 are already upgraded and do not need to be returned.

B) Identify the Serial Number on the Physical Board

See the location circled in this picture.

Note: The boards with matching serial numbers and part number 800-09307-10 are already upgraded and do not need to be returned.

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:

• Open a service request on Cisco.com
• By email
• By telephone

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