Comcast does IPv6 (in most areas, at least), AT&T does IPv6 (was 6rd when I was a customer), CenturyLink (or whatever they're called today) had 6rd on DSL when I was a customer... and it made their CPE do terrible things so it needed to be disabled, but it was offered. My muni fiber ISP offers IPv6.

> At this point it would be best to recognize the sunk cost and give up on the migration. IPv6 will never reach the 100% needed to turn off IPv4.

That was probably a reasonable take 15 years ago. But we're at 50% v6 globally, and the ISPs that are doing v6 + cgnat would not want to move all that v6 traffic to cgnat. v6 traffic is managed with stateless routing; cgnat is stateful and costly.

There are many lessons that can be learned, but v4 only is not the future. v6 only might never happen... people are going to keep running old software in emulation that will never support v6... But global routability of v4 will likely end one day. And I'd suspect the tail of the migration will be much shorter than the head was.

And I've only ever had v6, both on DOCSIS and fiber. Both observations are pretty useless in the grand scheme of things; actual adoption rates are what matter.

> At this point it would be best to recognize the sunk cost and give up on the migration.

That's a pretty wild thing to say in the comment section of an article about v6 reaching 50% eyeballs-side deployment.

> IPv6 will never reach the 100% needed to turn off IPv4.

As was predicted in 1994:

      Furthermore, we note that, in all probability, there will be IPv4
      hosts on the Internet effectively forever.  IPng must provide
      mechanisms to allow these hosts to communicate, even after IPng
      has become the dominant network layer protocol in the Internet.

Thugs are slowly moving. Another 5 years and most windows machines will support clat. Another 20 and most machines will hopefully support it. I wish it was embedded in the Linux kernel though as that increases the chance of your device working transparently on an IPv6 only subnet using slaac and the application creator doesn’t need to know anything other than their internal dhcp gets a 10.x address and everything works using 464.

I think the future is bright and most problems will be solved by 2040, and almost all by 2050.

I've had IPv6 addresses on Comcast, Spectrum, and Verizon FIOS.

If we have to give up on things that haven't reached 100%, shouldn't we give up on IPv4 first since that's even further away from 100%?