Re: IPv4 alongside IPv6
There are so many misrepresentations in that short post that it is hard to be succinct, sorry. TL;DR version: Wrong!
> access provider? Then you must provide IPv4 alongside IPv6 in order to connect your customers to the Internet
Yes, but you make it sound like that is a hard thing. Actually every ISP I know that provides dual-stack says it's easy. The very large providers prefer to provide IPv4 as a service over IPv6, and some are forced into 464XLAT (RFC6877) by the IPv4 address shortage.
> There is no sanctioned way for IPv6 Internet to access IPv4 content [except] NAT64/DNS64
That's kind of a backwards way of saying "NAT64/DNS64 supports IPv6 access to IPv4 content." Yes, it does fail in a few cases. So does NAT444. The same cases. Because the IPv4 Internet is out of f***ing addresses.
> content provider? Then you must put your content on IPv4 alongside IPv6, otherwise 90%+ of the world won't be able to see it.
Right, so you agree that 90%+ of the world will soon be on IPv6? Cool! And you're correct, content providers need to support IPv6 customers. Dual stack works, but if you want to be single stack, that's OK too:draft-ietf-v6ops-siit-dc will soon be here to help.
> deploying IPv6 does nothing to alleviate [IPv4] address depletion
Of course it doesn't. Nothing can alleviate it: it's a fact. Sorry if it's inconvenient.
> *rip and replace* the whole thing - with no compatibility between the two
That's simply a lie. Unless of course you have a new kind of mathematics in which more than 2**32 values can fit into 32 bits. If you do, please let us know. Or to say this another way: I've read every IPng alternative proposal since 1992, and none of them avoid the problem of needing either dual stack deployment or address type translation or both. All the rest is details.