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show chassis ssb



(M20 routers only) Display status information about the System and Switch Board (SSB).



Display information about all SSBs.


(Optional) Display information about the SSB in the specified slot. Replace slot with 0 or 1.

Required Privilege Level


Output Fields

Table 1 lists the output fields for theshow chassis ssb command. Output fields are listed in the approximate order in which they appear.

Table 1: show chassis ssb Output Fields

Field Name

Field Description


Number of times primary role has changed.


SSB slot number.


Current state of the SSB in this slot. State can be any one of the following:

  • Master—SSB is online, operating as primary.

  • Backup—SSB running as backup.

  • Empty—No SSB is present.


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

CPU utilization

Total percentage of the CPU being used by the SSB's processor.

Interrupt utilization

Of the total CPU being used by the SSB's processor, the percentage being used for interrupts.

Heap utilization

Percentage of heap space being used by the SSB's processor.

Buffer utilization

Percentage of buffer space being used by the SSB's processor.


Total DRAM available to the SSB's processor.

Start time

Time when the SSB started running.


How long the SSB has been up and running.

Sample Output

show chassis ssb

Release Information

Command introduced before Junos OS Release 7.4.