Hi @Stefan_Petersen,
ARC does not require a port forward for IPv6 in a native IPv6 environment or a true dual-stack environment. Many network setups will still require a firewall pinhole for the IPv6 address assigned to RoonServer - this is a process akin to port forwarding in the IPv6 environment.
However, the vast majority of LANs in our user base are still IPv4 or in a dual-stack lite setup with severe limitations on IPv6.
So, IPv6-related problems ensnare a far, far smaller percentage of our users than multiple-NAT environments created by dual-router setup or ISP implementation in the IPv4 realm. In our releases of ARC so far, we’ve targeted support language for IPv4 users. I understand that’s confusing - we’re constantly working on improvements to the mobile connectivity onboarding process.
From your post, it sounds like you’re currently able to access ARC on the go via your existing external IPv4 address. If you’re in a true dual-stack account tier, you can likely disable IPv4 and rely on the internal/external IPv6 addresses in place.