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Monitoring the Chassis

The chassis properties include the status of active chassis alarms on the Services Router, environment measurements, a summary of the field-replaceable units (FRUs), and the status of Physical Interface Modules (PIMs) on the router. To view these chassis properties, select Monitor>Chassis in the J-Web interface, or enter the following CLI show commands:

Caution: Do not install a combination of PIMs in a single chassis that exceeds the maximum power and heat capacity of the chassis. If J-series power management is enabled, PIMs that exceed the maximum power and heat limits remain offline when the chassis is powered on. To check PIM power and heat status, use the show chassis fpc and show chassis power-ratings commands. For more information, see the JUNOS Software with Enhanced Services J-series Services Router Getting Started Guide.

Table 10 summarizes key output fields in chassis displays.

Table 10: Summary of Key Chassis Output Fields



Additional Information

Alarm Summary 

Alarm Time

Date and time the alarm was first recorded.


Alarm Class

Severity class for this alarm: Minor or Major.

JUNOS has system-defined alarms and configurable alarms. System-defined alarms include FRU detection alarms (power supplies removed, for instance) and environmental alarms. The values for these alarms are defined within JUNOS.

Configurable alarms are set in either of the following ways:

  • In the J-Web configuration editor, on the Chassis>Alarm>interface-type page
  • In the CLI configuration editor, with the alarm statement at the [edit chassis] level of the configuration hierarchy

For details, see the JUNOS Enhanced Services Administration Guide.

Alarm Description

A brief synopsis of the alarm.

Environment Information  


Chassis component. For J-series Services Routers, the chassis components are the Routing Engine and the fans.


Gauge Status

Status of the temperature gauge on the specified hardware component.



Temperature of the air flowing past the hardware component.


Fan Status

Status of the fans that are regulated by JUNOS software:

  • OK
  • Testing (when the router is powered on)
  • Failed
  • Absent

Fan Speed

Speed of the fans: normal or high speed.

Speed is adjusted automatically according to the current temperature.

Hardware Summary  


Chassis component.

On J-series Services Routers, an FPC and a PIM are the same physical unit. The PIM number is always 0.


Revision level of the specified hardware component.

Supply the version number when reporting any hardware problems to customer support.

Part Number

Part number of the chassis component.


Serial Number

Serial number of the chassis component. The serial number of the backplane is also the serial number of the router chassis.

Use this serial number when you need to contact customer support about the router chassis.


Brief description of the hardware item.

For J-series PIMs, the description lists the number and type of the ports on the PIM—identified in the display as a PIC.

FPC Summary


FPC or PIM slot number.

On J-series Services Routers, an FPC and a PIM are the same physical unit.


State of the slot:

  • Dead—Held in reset because of errors.
  • Diag—Slot is being ignored while the FPC or PIM is running diagnostics.
  • Dormant—Held in reset.
  • Empty—No FPC or PIM is present.
  • Online—FPC or PIM is online and running.
  • Probed—Probe is complete. The FPC is awaiting restart of the Packet Forwarding Engine (PFE).
  • Probe-wait—The FPC is waiting to be probed.

Temp (C)

Temperature of the air passing by the FPC, in degrees Celsius.

J-series Services Routers do not monitor and report the temperature of PIMs.

CPU Utilization (%)

Total—Total percentage of CPU being used by the FPC or PIM processor.

Interrupt—Of the total CPU being used by the FPC or PIM processor, the percentage being used for interrupts.


Memory DRAM (MB)

Total DRAM, in megabytes, available to the FPC or PIM processor.


Utilization (%)

Heap—Percentage of heap space (dynamic memory) being used by the FPC or PIM processor.

Buffer—Percentage of buffer space being used by the FPC or PIM processor for buffering internal messages.

If the heap space utilization exceeds 80 percent, a memory leak might be occurring.

For more information about the J-Web Monitor task, see Monitor Tasks.

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