Thank you for your patience as we’ve merged several posts from users here who are stranded without port forwarding as a result of the carrier-grade network address translation implemented by Deutsche Glasfasaer.
To clarify where things stand, more broadly:
At this time, Roon ARC requires an external (WAN) IPv4 address for port forwarding and on-the-go connectivity. Similarly, Roon ARC requires the Core to have an address in the IPv4 format, as it doesn’t yet support IPv6 at this time. Fiber optic networks in Germany have fully adopted IPv6 with Dual-Stack Lite to accommodate outbound/inbound IPv4 traffic. In many implementations, this is an innavigable situation for Roon ARC. Your router will generally have a routable IPv6 address automatically, and if you designate an IPv4 address, it will be translated through a shared IPv4 address via CG-NAT.
Some users, as discussed above, can request a routable IPv4 address for their account to bypass CG-NAT, sometimes for a monthly or flat fee. I do not believe Deutsche Glasfaser offers this, although it is always worth checking with their support team, as fiber users from other providers have encountered occasional lucky results.
That said, there are several VPN and proxy-server solutions in the #roon and #tinkering sections that users have configured as workarounds. Common basic consumer solutions include NordVPN or other common VPNs, and Tailscale . Note that the support team will be unable to assist with VPN configuration, but we can help guide you to popular threads with solutions other users have found for their own use cases.
Roon is actively working to implement workarounds for IPv6 and CG-NAT to enable ARC functionality for users such as yourselves. We’re also researching alternatives to port forwarding for future releases of ARC; rest assured this is just how it works at the moment.
Thank you for your patience.