Cannot connect to ARC outside my network

Support ARC: Port Forwarding Help
2

Hey @Jan_Paul_van_Vliet,

Thanks for writing in! In some cases enabling UPnP by itself won’t be enough, you’ll need to set up port forwarding and put in your NAS name, the NAS IP address, and the Roon default port (55000.)

Here is an excellent step by step on setting up port forwarding with your router: Fastest Netgear WNDR4000 Router Open Port Guide

With that, here is a helpful article on Port forwarding for arc :