Description

The "OCM parity error" message reports a hardware parity error in the XMCHIP OCM block.

This is a Troubleshooting Article for a PFE ASIC Syslog Event.
To view other documented syslog events related to XMCHIP, XLCHIP, MQCHIP, LUCHIP, EACHIP, and PECHIP, see KB31893 - Master Index of Articles for Troubleshooting PFE ASIC Syslog Events [juniper.net] .

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Symptoms

When a "OCM parity error" event occurs, a message similar to the following is reported: 

Apr 5 02:48:42 router0 : %PFE-3: fpc7 XMCHIP(2): OCM: LO0 parity error - Parity Error Address 0x12f62, Bank 0x8000, Data 0xb2621000000443
Apr 5 02:48:42 router0 : %PFE-3: fpc7 XMCHIP(2): OCM: LO1 parity error - Parity Error Address 0x8e88, Bank 0x8000, Data 0x6e32801bb000000
Apr 5 02:48:42 router0 : %PFE-3: fpc7 XMCHIP(2): OCM: DDR0 parity error - Parity Error Address 0x6868, Bank 0x8000, Data 0xb4fbf23c118ea7

Indications:

  • Single occurrence of syslog, not seen with other events, indicates one time hardware error. Multiple continuous occurrences indicate persistent underlying issues.

  • Traffic impact or permanent impact on packet forwarding may happen if errors are seen frequently​  

 

Solution

This is due to a transient hardware error being detected in the OCM block of the XMCHIP.

 

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Perform these steps to determine the cause and resolve the problem (if any).  Continue through each step until the problem is resolved.

  1. Collect the show command output.

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    Capture the output to a file (in case you have to open a technical support case). To do this, configure each SSH client/terminal emulator to log your session.

    show log messages
    show log chassisd
    start shell network pfe <fpc#>
    show nvram
    show syslog messages
    exit

Analyze the show command output.

In the 'show log messages', review the events that occurred at or just before the appearance of the "OCM parity error" message. Frequently these events help identify the cause.

  • No RMA required.

  • FPC restart  during a maintenance window should clear this error.

  • The multiple continuous occurrences of errors require  FPC restart during a maintenance window to clear the alarms.

  • Contact your technical support representative to investigate further if the issue is seen after FPC restart.

This article is indexed in  KB31893 - primary Index of Articles for Troubleshooting PFE ASIC Syslog Events [juniper.net] ; tag XMCHIPTSG


Tip: When looking at an event in the logs, it is important to focus on the first error message in a collection of syslog messages. The first error message is usually the cause of all the follow-on error messages. The follow-on collateral damage error messages can be ignored.

 

Modification History

2019-10-14: Article reviewed for accuracy; no changes required.