Juniper Networks Technical Assistance Center; Troubleshoot The Fan Tray; Troubleshoot Packet Forwarding Engine Components - Juniper M10 Hardware Manual

Troubleshoot Packet Forwarding Engine Components

Juniper Networks Technical Assistance Center

If you need assistance during troubleshooting, you can contact the Juniper Networks Technical
Assistance Center (JTAC) by e-mail or telephone. See "How to Request Support" on page xix.

Troubleshoot the Fan Tray

The fan tray installed along one side of the chassis houses four fans that draw room air into
the chassis to maintain an acceptable operating temperature for the Routing Engine, PICs,
FEB, and other components. For a graphic depiction of the airflow, see Figure 10.
For the fan tray to function properly, the clearance around the chassis must be sufficient for
unobstructed airflow. See "Clearance Requirements for Airflow and Hardware Maintenance"
on page 40.
Temperature sensors on the components detect temperatures above the acceptable range.
Fan failure or an excessive temperature condition triggers the red alarm LED on the craft
interface. If the temperature passes the acceptable maximum, the Routing Engine shuts
down the router by turning off the power supplies.
To troubleshoot the fan tray, follow these guidelines:
Troubleshoot Packet Forwarding Engine Components
The following sections describe how to troubleshoot the FEB and PICs:
124
M5 and M10 Internet Routers Hardware Guide
•
Check the status of the fans in the fan tray by issuing the show chassis environment
command. The output includes an entry for each fan, as shown in this example:
user@host> show chassis environment
Class Item
...
Fans Left Fan 1
Left Fan 2
Left Fan 3
Left Fan 4
...
For further description of the output from the command, see the JUNOS Internet
Software Operational Mode Command Reference: Protocols, Class of Service, Chassis,
and Management.
•
If the fan tray fails, determine whether you can distinguish individual blades in a
fan—this is not possible when the fans are rotating at normal speed.
•
Troubleshoot the FEB on page 125
•
Troubleshoot PICs on page 125
Status Measurement
OK Spinning at normal speed
OK Spinning at normal speed
OK Spinning at normal speed
OK Spinning at normal speed