An alarm is generated on a switch port when the device on the other side (also a switch) is placed in Maintenance Mode.
This is the scenario:
Device A and Device B are connected. Device B is the upstream device.
Device A is put in Maintenance Mode and it goes down.
Device B's port throws a critical alarm (Interface Down).
Release : 20.2
Component : Spectrum Alarm & Event Management
The behavior you reported is expected.
Device A is put in Maintenance mode. Hence there is no alarm on this device model.
But as the Live Pipe/Link is enabled, the ok_to_poll (ox11dd8) attribute ID is enabled on both sides of the pipe/link, hence the attribute is set to Yes on both interfaces from Device A and B.
When you shut down Device A, the ifOperStatus of the interface of Device B connected to Device A will be down, hence the Interface Down alarm is generated (because Live Pipe/Link is enabled).
In the picture below, the device was put in Maintenance Mode after the device is down:
In the picture below the device was put in Maintenance Mode prior to the device being down:
If you also put the interface model of Device A in Maintenance Mode, then the alarm will not be generated on the other side of the Pipe/Link (Device B), it will be suppressed.
OOB (Out Of the Box) the sub-models (like ports and applications) do not inherit the maintenance mode from the parent model (device model).
You will have to change the following attributes to Yes/True on the device model:
The ports and applications models will inherit the Maintenance mode from the parent model (device model).
This is covered in the following section of the Spectrum guide:
Show Brown Alarms for Interfaces and Applications
You can display brown alarms for interfaces and applications that have inherited maintenance or hibernation mode from the device model by using the DX NetOps Spectrum Command Line Interface (CLI).