I called my ISP and they assured me that all ports are open on their end and that if I set up port forwarding on my system, which I have, it should work, However, they do use IPV6…. I’m wondering if that’s the problem.
I have two homes and I have easily set this up successfully in the other home on my Bell 3000 router. I use the same NUC in both locations - I take the NUC from house to house.
@Ian_Hudson, it appears your ISP, Wightham Telecom, uses CGNAT (Carrier Grade NAT) in their network based on 100.64.xxx.yyy address in your ARC error message. At the present time, ARC cannot work on network using CGNAT. CGNAT is used in some cases to provide multiple users with a shared IP address that are in short supply.
Can you contact Wightham and see if they can either turn off CGNAT for your account or if there is an option for you to get a public/routable IPv4 address?
Thank you for reporting in on your progress, and I’m very sorry to hear that you’re joining the ARC users stranded by carrier-grade NAT without paying extra to your provider.
Note that Roon is diligently researching alternative solutions to port forwarding and additional workarounds in the meantime that will help democratize access to mobile playback to more users, regardless of the infrastructure of their service provider. Your posts here will assist in this effort, and I’ll add your service provider shortly to the list of known CG-NAT blockages here: ISPs and Routers: List of Known Solutions and Workarounds