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Cisco MGX 8800 Series Switches

Field Notice: MGX8850 Potential PXM1 Loss of Database Synchronization


August 7, 2000



Products Affected

Product

Comments

PXM1

MGX 8850 Processor Switch Module 1 front card

mgx8850-fw-1123

ANY release prior to 1.1.24.

Problem Description

On occasion switch-cc problems have been discovered when using the clrsmcnf command on a CESM or FRSM Service Module. Root cause is bug CSCdr38391 (fixed in release 1.1.24) which can stop synchronization of the active and standby PXM databases. If you are a registered CCO user and have logged in, go to the Bug Toolkit at http://www.cisco.com/kobayashi/bugs/bugs.html and enter the bug ID in the Bug ID field to view more information about the bug.

Problem Symptoms

Each clrsmcnf command issued on a CESM or FRSM causes a change in the database state on the active PXM1 card. From that point on, database changes from the active card are not written to the standby and data for connections and interfaces can be compromised when a subsequent switchcc command is executed.

Background

This anomaly was originally discovered using clrsmcnf on CESM, which is reported under bug number CSCdr38391 and fixed in release 1.1.24.

Workaround/Solution

Cisco recommends at this time that operations requiring the use of the clrsmcnf command on CESM or FRSM be avoided until the MGX8850s are upgraded to software level 1.1.24 or higher. If however it becomes necessary to use the clrsmcnf command, please avoid further provisioning on the affected node and notify us at www.cisco.com (open a case on-line) so that we can work with you to restore database synchronization to normal operation.

Take steps where possible to save the active configuration before entering the switchcc command. If a switchcc does become necessary, then the active configuration should be saved. If there are problems evident after the switchcc then restore from the saved configuration and reset the standby PXM to ensure synchronization with the newly active PXM.

In addition, Cisco recommends that MGX8850 nodes which might have had clrsmcnf used on them have their logs checked for messages associated with database synchronization problems.

Example log entries (command=dsplog)

08/01/2000-23:50:19 08 tPMM PMM-7-FSM_RPT 
      FSM Report: Send peer to Fail, cur=PMM_ACTIVE_STATE, evt=DNLD_EVT 
      08/01/2000-23:50:19 08 tPMM PMM-4-RED_STATUS
      Redundancy Status Change for bit PEER_DB_OUT_OF_SYNC now OK 
      08/01/2000-23:50:19 08 tDBM DBM-2-SYNCFAIL 
      Database Sync to standby card failed. Unable to establish Core Redundancy.

Other Considerations

Note:?Should this problem occur, it will persist until corrected.

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: