JATP all-in-one appliance alerts eth1 down, when it is not in use.
Juniper ATP on-prem appliances that are installed as an "all-in-one" type appliance use the eth1 interface for collecting traffic. If this interface is not connected, an alert is generated. This is expected behavior.If you are not using the collector function of the appliance, it is safe to ignore this alert.
Alternatively, you can consider converting the form factor of the device to Core/Central Manager to stop eth1 from alarming.
2023-04-19 -- Initial Draft2023-04-20 -- Symptoms Updated2024-02-26 -- Solution Clarified2024-03-05 -- Minor edits, Related Information
All-in-One Quick Start Guide - Changing the Appliance Type