> Is IPv6 really that widely used?
Mobile carriers use it almost exclusively, which is already a huge chunk of the internet, and newer ISPs are switching to it too.
> I'm supporting both because I heard it's good to support both, but I'm not sure what the actual benefit is.
The benefit is that you allow IPv4-only and IPv6-only clients to connect.
I accidentally became the user of an IPv6-only device a while back for some obscure reason I never could figure out. Let me tell you: There are no IPv6-only users. Absolutely nothing except Google, Facebook, and YouTube works. Any website not in the top 20 are IPv4-only. It was so bad I briefly thought I didn't have an internet connection at all. Anyone stuck on an IPv6-only connection would immediately cancel their contract on the grounds that they don't have de-facto internet access.
So, like, the three most popular things still worked. I wonder if working more is related to their popularity.
I think it's more that Google and Meta have the surplus engineering resources to implement IPv6 for what is essentially no reason.
Probably for lower latency and higher reliability on mobile networks.
You can do IPv6 only if you have a 64 nat on your edge and use dns64 and just use a limited set of applications and devices.
Some applications will still fail to work though unless you also have 46 nat on your device which still doesn’t work transparently on majority of types of device.
You also need all devices on your lan to support v6 natively, and v6 only. From your printer to your speaker.
You might be able to do something with mdns and nat64 to get them working on an IPv4 only subnet. But you’re talking layers and layers of complexity for things which just have to work.
I’m posting this from my phone on my IPv6 only subnet, not sure if it’s using a 64 gateway or 6 native to HN, but it’s possible.
All the more reason to support it. There are lots of ISPs that only assign you an IPv6, and do hacky trickery to make IPv4 work over that. We wouldn’t need all of this.