Looking at the 'Devices / Socket Filter Agent' pane within the PAM Client we can see that the list of Socket Filter Agents can show different statuses: Active, Inactive and Unknown.
This document tells about the situations that lead to these different statuses.
What is the meaning of the different Socket Filter Agent's statuses?
Any PAM server installation having the Socket Filter Agent software integrated in the endpoints.
In order to properly report the Socket Filter Agents status, there is a process in the PAM server that checks their connections at regular intervals.