Or perhaps the separate lan with a Pi providing a bridge. https://www.youtube.com/watch?v=8mHXwmULOvk https://www.youtube.com/watch?v=8mHXwmULOvk Set your firew

Or perhaps the separate lan with a Pi providing a bridge. https://www.youtube.com/watch?v=8mHXwmULOvk https://www.youtube.com/watch?v=8mHXwmULOvk Set your firewall rules as you like.