However, simply shutting down all open ports isn't a practical solution, as it'll hamper your internet connectivity. Common ports like 80 (HTTP), 443 (HTTPS), and 53 (DNS) should be left open.

I'm trying to have the Cinema 4D Net Render Server listen on port 80. When I do, it tell me the port is in use. It works fine over 8080, I'm just trying to make a it a bit simpler for my users to ...