The "FO: Request timeout error" message reports that the forwarding ASIC is not able to send packets via fabric to another PFE. When the forwarding ASIC needs to send traffic over the fabric to another PFE, it makes a request to the destination PFE and waits for the reply. If there has been no reply, the forwarding ASIC report "FO: Request timeout error" together with the stream number corresponding to the destination PFE. Hence, the "FO: Request timeout error" is not necessary an indication that there is any error with the FPC reporting the error.

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 "FO: Request timeout error" event occurs, a message similar to the following is reported:

Jul 25 16:12:23.535 router0: %PFE-3: fpc8 MQSS(0): FO: Request timeout error - Number of timeouts 0, RC select 3, Stream 160

Indications: 

• No traffic impact on single occurrences
• If errors are seen repeatedly there might be traffic impact

This is due to another PFE / FPC going down or not responding, or packets being dropped from the reporting PFE through the fabric to the destination PFE.  The EACHIP on this FPC is only reporting the issue and is not the source of the problem.

RECOMMENDED ACTION:

• The FPC reporting this error usually does not have the problem. Do not reboot the FPC.
• Review /var/log/messages for errors reported from other FPCs or Fabric planes
• Collect the following information and contact JTAC:
  • Output of "request support information | no-more"
  • Content of /var/log directory

{DIDYOUKNOWSERVICENOWTOKEN.EN_US}

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.

   {SYSLOGSERVICENOWTOKEN.EN_US}

   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 "FO: Request timeout error" message. Frequently, these events help identify the cause.

• Fabric resiliency will automatically recover from such condition and take corrective actions
• Contact your technical support representative if this event is reported repeatedly to isolate the fault area

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