You have a endpoint agent (any version), and have not seen it check in to the Agents Overview section, nor have you seen any incidents created from this agent.
You may first want to check out port connectivity from the endpoint agent to the endpoint server via a telnet test.
Additionally you can use the windows netstat utility to see if the endpoint agent has an "established" connection or not.
If your Endpoint server IP address is, 192.168.2.52 You can perform the following telnet test from a endpoint agent that is not checking in.
open a Command window:
telnet 192.168.2.52 10443
Another good test you can perform from the Endpoint Server is a netstat test which will show you what ports are connected/established or listening.
The endpoint server should be listening on port 10443 (0.0.0.0:10443 LISTENING), The endpoint agent, if connected will show ESTABLISHED on port 10443
Example From Endpoint server:
TCP 0.0.0.0:10443 0.0.0.0:0 LISTENING 2192
TCP 192.168.2.52:10443 192.168.2.53:1433 ESTABLISHED 2192
TCP 192.168.2.52:10443 192.168.2.54:49306 ESTABLISHED 2192
TCP 192.168.2.52:10443 192.168.2.55:49160 ESTABLISHED 2192
(Note that pre DLP version 12.5 your Endpoint Agents may be communicating on port 8000)
To test the endpoint agent's ability to communicate with the endpoint server, use the following command
It is unreliable to test netstat on the Endpoint Agent as this will only show established if the Agent is actively transferring data from the endpoint server. You will not observe any output on the endpoint agent port otherwise. Endpoint agents attempt a connection with the endpoint server as per the agent Polling interval. This interval is located in the advanced settings of the agent configuration (ServerCommunicator.CONNECT_POLLING_INTERVAL_SECONDS.int)