That's the point - you don't need to know your stack. You don't need to worry if CUPS is installed, enabled, or listening on your interface. You don't need any

That's the point - you don't need to know your stack. You don't need to worry if CUPS is installed, enabled, or listening on your interface. You don't need any of that, as long as you do the bare minimum and configure your firewall. That's the whole point!!!