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Hierarchy Level


Configure an alarm input or output on the dedicated alarm port on the router. You can use the alarm input configuration to receive alarm inputs from the external devices such as sensors. You can use the alarm output configuration to relay the alarms in the router to external alarm devices. You can configure up to three alarm inputs and one alarm output.



Specify the port number for the alarm input or output. The system supports up to three alarm input ports (port number: 1 to 3). The system supports only one alarm output port (port number: 1)


Applicable only to alarm inputs.

Configure a signal polarity for the alarm input based on the user environment. The alarm relay becomes operational when the input signal polarity is high or low based on this configuration. The following options are available.

  • high

  • low

  • Default: low


Specify the administrative state of the alarms.

  • disabled—Disable the alarm configuration. If you choose this option, the router will not trigger the alarm configured on this port. Disabling an alarm configuration does not delete the alarm. You can enable it when required.

  • enabled—Enable the alarm configuration.

  • Default: disabled

description description

Provide a description for the alarm input or output. For example, you can provide a description to identify the device connected to the alarm port.


Applicable only to alarm inputs.

Configure an alarm severity. The system supports the following alarm severities.

  • critical

  • major

  • minor

  • warning


The system considers the alarm inputs configured with the critical or major severity as major alarms. The alarm inputs configured with the minor or warning severity are considered minor alarms.

  • Default: critical

Required Privilege Level

interface—To view this statement in the configuration.

interface-control—To add this statement to the configuration.

Release Information

Statement introduced before Junos OS Release 20.2R1.