Is it possible to set different ports for external access and for listening on the Roon Server in Roon ARC?
Currently, I am using the iOS Roon ARC app to access my home router and listen to music while away from home. However, as it stands, external access is directed to the Roon ARC port specified in the Roon Server settings on the router, and the router's NAT forwards that same port number directly to the local PC with the same port number. This setup raises security concerns for me, so I would like to modify the NAT settings to change the port number. However, I am unsure how to do this. If port translation is possible, I would appreciate it if you could explain how to set it up. If it is not possible, I would also appreciate confirmation of that.
Describe your network setup
manufacturer of my home router: NEC model: Aterm WX1500HP
You don’t need port translation. You can choose any port number you wish (at least within the set of ports supported by your router/ISP combination).
Thus, if you are worried about using port numbers that are in common use, then just set the Roon ARC port (in Roon → Settings → Roon ARC) to any port number (between 1025 and 65535) that isn’t already in use in your network.
Port translation would not add to your network security. Beyond adding the possibility to run multiple servers on the same (internal) port (e.g. Web Servers on Port 80), It is only a mechanism to avoid using guessable ports - and with Roon you can already do that.