Earlier quoted context omitted.
At this point it's not so much the basic devices, it's very rare to have hardware still around that doesn't support ipv6, it's more the configuration of the networks themselves, as any given network needs to have its own set of decisions made on address allocation, etc to actuallly support it. And, since it's used by fewer people and there always needs to be a fallback to ipv4, for most networks the if ipv6 is broken…
> flip a switch and it'll mirror your ipv4 setup so you don't have to think about it until you locally need more address space If you think about it, that is what dual-stack is. You don't have to do anything unless you want more address space. The issue is that often locally one doesn't need more address space, but the Internet as a whole does.
Re: The mistakes and missed opportunities in the design of IPv6
#71No, it's not really the same thing: with dual-stack you do need to think about your IPv6 configuration quite deeply, you can't just copy and paste what you're doing in IPv4, even if what you're doing in IPv4 could work just fine with essentially a fixed prefix on all your own addresses. (that said, I'm sure there's subtlety to this which makes it not so easy to implement as a standard. But AFAIK it wasn't even really a goal of IPv6)