How to trace internal IP addresses

Hi All

Maybe a noob question but I know nothing about docker, containers etc and run HA OS standalone on a NUC (supervised)

I have been getting errors like the following in NGNIX and my question is how do I trace what part or add-on in HA is using / has that IP address?

2021/10/01 17:53:22 [error] 221#221: *12709 recv() failed (104: Connection reset by peer) while proxying upgraded connection, client:, server: MY_DOMAIN.COM, request: "GET /api/websocket HTTP/1.1", upstream: "", host: "MY_DOMAIN.COM"

I commonly see entries across HA that list internal IP’s like this and have never discovered how to work them out?


I’d be very interesting to know that too since I see similar errors in the log.