[moduspwnens14]

Apple has been requiring all apps on the App Store work on IPv6-only networks for two years now [1]. They require it work on a network with NAT64 and DNS64 set up.

Essentially your device gets only an IPv6 address and the router translates IPv4 addresses to IPv6 ones. Your DNS server does the same thing. The end result is that your device talks only native IPv6, but the router is translating back and forth as necessary for IPv4.

It's actually pretty easy to test if you have an extra Mac laying around. There's a hidden checkbox on the Network preferences pane that lets any Mac create a NAT64 / DNS64 WiFi network [2].

[1] https://developer.apple.com/support/ipv6/ [2] https://developer.apple.com/library/archive/documentation/Ne...