- Who is your internet service provider?
- Please list the make and model of your modem and router?
Sunrise Internet Box
- Do you have any additional network hardware, like additional routers or managed switches?
Yes, wifi router and access point
- Does your network have any VPNs, proxy servers, or enterprise-grade security?
What is the exact port forwarding error message you see in the Roon Settings → ARC tab?
I had an issue with Roon suggesting dual NAT.
I solved it by going to the Sunrise community page and asking whether CGNAT is active. Their response was that by default, clients are connected over IPv6, however upon asking they will migrate you to IPv4.
Worked like a charm, I am now happily using RoonARC.
Just thought it would be useful to know for other Sunrise users. Chat or phone support don’t know how to deal with this issue, the community forum is the way to go.