[JimDabell]

One thing I appreciate about Apple’s App Store rules is that they require all apps to work on IPv6-only networks. They’ve had that rule in place for many years. It’s a little surprising as a developer the first time you run into it, but I’m glad it’s there as a user.

[Gigachad]

Is github accessible by v6 as long as you use the app?

[xvilka]

GitHub doesn't support IPv6 yet[1]. Ridiculous but true.

[1] https://github.com/orgs/community/discussions/10539

[neilalexander]

No, their policy is that you have to use IPv6-capable sockets and APIs, not that the remote endpoints are accessible over IPv6.

[lostmsu]

That's, effectively, a non-policy.

[WorldMaker]

It does more than you think it does. GitHub may not support IPv6 and Apple can't force them, too, but the GitHub App on iOS is in most cases using DNS64 to get an IPv6 address to a NAT64 gateway to the GitHub IPv4 addresses, and all that just works today, in part because Apple forced apps to support "I'm always going to give you an IPv6 address, even if you know your own service isn't going to naturally return one".

[lostmsu]

I was not proficient enough to understand that on my own. ELI5 is that this requirement forces apps to support running on IPv6-only networks where DNS calls return special IPv6 addresses for IPv4 hosts and ISP (usually mobile) does IPv6 to IPv4 NAT. That does sound useful.

[WorldMaker]

Right. It's useful to point out too that for some of our day-to-day mobile networks this is the present state and not just a hypothetical future. Mobile and cell networks have been a driving force for IPv6 adoption [1] and several of them went IPv6-only infrastructure years ago (hand in hand with 5G rollouts in many cases). Both iOS and Androids efforts in making sure that IPv6-only was standard and worked in all App Store/Play Store apps were critical to getting us here.

[1] IPv6 makes hand-offs between radio towers (cells) a lot easier if the towers don't also have to manage scarce IPv4 addresses/NAT44 configurations and complicated DHCPv4 handshakes to setup/change IP addresses regularly; plus mobile networks in general have a lot of devices today, some have way more than other types of ISPs so IPv4 scarcity was something they could feel directly on their corporate bottom lines.

[Sesse__]

”v6-only” in this context generally means ”with NAT64”, so only kind of.

[the_mitsuhiko]

Yes, but it does not require your server to have an IPv6 address.