Cisco MGX 8230 Software

Field Notice: write memory Problem with MGX 1.2.01 Software

May 14, 2002

Products Affected




In an MGX8200 running 1.2.01 switch software Cisco IOS® Software Releases 12.2(4)T, 12.2(4)T1, 12.2(4)T2, 12.2(4)T3


In an MGX8200 running 1.2.01 switch software Cisco IOS Software Releases 12.2(4)T, 12.2(4)T1, 12.2(4)T2, 12.2(4)T3


In an MGX8200 running 1.2.01 switch software Cisco IOS Software Releases 12.2(4)T, 12.2(4)T1, 12.2(4)T2, 12.2(4)T3

Problem Description

After a power cycle or reboot, the Route Processor Module (RPM) fails to download a saved configuration file.

The write memory command, which saves the current configuration to the PXM1 hard drive, corrupts the configuration file. Subsequent reboots or power cycles of the affected RPM cards result in a failure to load the saved configuration file and interrupt traffic. This problem was introduced in MGX software release 1.2.01.

For the purposes of this field notice, RPM refers collectively to these three cards:

  • MGX-RPM-128M/B RPM-128 MB DRAM




Combinations of MGX-1 PXM image 1.2.01 and Cisco IOS RPM Software Release 12.2(4)T, 12.2(4)T1, 12.2(4)T2, or 12.2(4)T3 result in a configuration file corruption with the issue of the write memory command.

Customers have been encouraged to issue the write memory command with each change in the RPM configuration to preserve the latest configuration should the RPM reboot or go through a power cycle. This anomaly corrupts the saved configuration file so it is unusable.

The problem occurs only when you configure the startup configuration to be the C:auto_config_slot file and when you save the running configuration onto the startup configuration. In the case of 1:N redundancy, by default, the startup configuration is configured to be the C:auto_config_slot file; so this anomaly also applies for 1:N configuration.

This problem is not seen with the PXM image 1.2.00 and Cisco IOS RPM Software Release 12.2(4)Tx combination.

Problem Symptoms

After an RPM reload or RPM failover to a redundant card, the user may lose configuration and fail to process traffic.

There is an incorrect logic in the writing of the tag. A tag is usually the last line of a configuration file and contains the time and date when the configuration was saved. A fix for Cisco bug ID CSCdw41946 introduced an issue with backward compatibility of PXM and Cisco IOS Software images. This bug fix works with later Cisco IOS Software images, but does not work with early images such as Cisco IOS Software Release 12.2(4)T, 12.2(4)T1, 12.2(4)T2, and 12.2(4)T3.



Instead of using the write memory command, complete these two steps to save the configuration properly on the PXM disk.

  1. Issue the copy run bootflash:[dummy-file-name] command.

    It is best to name the dummy file "start-up" to increase readability. Since you are not writing to the disk, the tag is not added.

  2. Issue the copy bootflash:[dummy-file-name] start command.

    Since you are saving a file from bootflash to the startup, this also works well.


Download MGX software and Cisco IOS Software pairs that are compatible. Cisco IOS Software Release 1.2.02 has the fix for this anomaly. Cisco IOS Software Release 1.2.02 may be downloaded from


To follow the bug ID link below and see detailed bug information, you must be a registered user and you must be logged in.




Configuration gets corrupted after write memory in Cisco IOS Software Release 12.2(4)T3 image.

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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