[alienth]

We (reddit) were blocked by AWS on this until 2017 or so. Since then it's mostly been an issue of reworking internal tooling and storage. There are a huge number of places we'd need to futz with to support IPv6, and to be honest we've had basically zero pressure to do so.

When pressure is zero and effort is high, things will go unchanged. I'm sure once pressure exists then some movement will occur. It seems most of the industry is doing everything they can to put off incurring pressure, though.

[commandersaki]

Thanks to CGNAT we have shifted from a 32-bit to a 48-bit address space (since the port is now part of the address).

Ipv6 really only serves to shed load off CGNAT since we rely on the continued use of v4 addresses since v6 is not interoperable with v4.

But why should Reddit support v6? For the greater good of v4 by reducing pressure of CGNAT for dual homed users. But wait, who are the dual homed users you may ask? Mobile users. And it will only be mobile users since autoconfiguring residental networks to dual home is not going to happen. But Mobile carriers have full control of addressing and TCP/IP configuration of handsets, and so they can easily deploy usable v6.

So the smaller sites shouldn't bother with v6 because they're not an essential part of the Internet with large traffic. But a site like Reddit can reduce enormous pressure for mobile carriers to deliver use of the Internet.

[miyuru]

what about deploying IPv6 via your CDN(Fastly) on the frontend?