The "Corrected single bit ECC error" message is likely caused due to transient Hardware

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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When a "Corrected single bit ECC error" event occurs messages similar of the following are reported:

EACHIP:

Sep 7 13:40:01.556 router : %PFE-5: fpc8 EA[0:0].idmem_slice[0].protect ERR 30 Corrected single bit ECC error @ 0xfbf80005.
Sep 7 13:40:04.554 router : %PFE-5: fpc8 EA[0:0].idmem_slice[0].protect ERR 31 Corrected single bit ECC error @ 0xfbf80005.

Sep 7 13:40:09.579 router : %PFE-6: fpc8 Error (0x40018), module: LKUP-EA[0:0], type: Single-bit ECC error
Sep 7 13:40:09.579 router : %PFE-7: fpc8 Cmerror: Level 0 count 1 (occur_count 1 clear_count 0)crossed threshold 1 action 0x5
Sep 7 13:40:09.579 router : %PFE-7: fpc8 cmerror_take_action_helper: performing action 1 for level 0 err_id 262168 module id 24
Sep 7 13:40:09.579 router : %PFE-7: fpc8 cmerror_take_action_helper: performing action 4 for level 0 err_id 262168 module id 24
Sep 7 13:40:09.579 router : %PFE-3: fpc8 Cmerror Op Set: LKUP-EA[0:0]: EA[0:0].idmem_slice[0].protect ERR 32 Corrected Single bit ECC error @ 0xfbf80005.

XLCHIP:

Sep 7 13:42:11.921 router : : %PFE-5: fpc10 XL[0:0].idmem_slice[0].protect ERR 30 Corrected single bit ECC error @ 0x7bfa0005.
Sep 7 13:42:11.921 router : : %PFE-5: fpc10 XL[0:0].idmem_slice[0].protect ERR 31 Corrected single bit ECC error @ 0x7bfa0005.

Sep 7 13:42:12.715 router : : %PFE-6: fpc10 Error (0x40018), module: XL[0:0], type: Single-bit ECC error
Sep 7 13:42:12.813 router : : %PFE-7: fpc10 Cmerror: Level 0 count 1 (occur_count 1 clear_count 0)crossed threshold 1 action 0x4
Sep 7 13:42:12.937 router : : %PFE-7: fpc10 cmerror_take_action_helper: performing action 4 for level 0 err_id 262168 module id 9
Sep 7 13:42:13.062 router : : %PFE-3: fpc10 Cmerror Op Set: XL[0:0]: XL[0:0].idmem_slice[0].protect ERR 32 Corrected Single bit ECC error @ 0x7bfa0005.

Indications:

• No service impact

• Minor alarm is raised if corrected events reach 32 within a 24 hours window

Onchip IDMEM memory is ECC protected. If the number of single-bit ECC correction reaches 32 event within 24 hours, an CMERROR Minor Alarm Single-bit ECC error is reported. The counter will be reset every day change. Single bit ECC errors will be corrected

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.

   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

2. Analyze the show command output.

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

• No RMA required.

• If errors are seen from the same address location after minor alarm is raised, collect data with  KB31922 - shell script collecting data if packet forwarding at Packet Forwarding Engine is compromised [juniper.net]

• Collect any debug and ttrace files if found in /var/tmp

• Contact your technical support representative if the event is reported after FPC restart

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