The world in which IPv6 was a good design

Actually, facebook has a great problem tracking me between sites, because I make sure that they have these great problems (by using different VMs for different aspects of my works and life, none with access to hardware acceleration, by using proper web filtering at both the browser and gateway level). They have it easy with the vast majority of the population, no doubt, but for now my actions gets mixed with everyone elses in such a way that Facebook would actually have to assign a person to deanonymize me. Similarly Google.

My ISP can quickly deanonymize me, but at this point in time they don't unless they get a government request (I'd be surprised if they actually demand a warrant). Switching to IPv6 would effectively deanonymize me constantly.

> And allow all other ports, hopefully? Peer-to-peer infrastructure is not going to run over HTTP and email. It's going to run over brand new protocols and ecosystems, many of which are sitting in a variety of research papers waiting to be implemented.

That's a great ideal. No, they don't allow all other ports, but what they allow or block varies a lot by service class, area and ISP, and you'd know for sure only after you tried (it used to also change often, but I heard it's converged; I'm not living in the US anymore)

> Which require, of course, somebody running a centralised server and willing to pay for the bandwidth of TURN. This outright prevents proper peer-to-peer infrastructure from happening - the people running these services need to pay for them somehow. Even working around it via e.g. Skype's "supernodes" is expensive in terms of developer cost and the amount of expertise needed to create such a system.

Supernodes were retired because they do not work well anymore (haven't in a few years). I do not find "pay $1/month to provide service" too onerous; there are also public ICE/STUN/TURN.

I find it disingenuous that you completely dismiss the societal cost (privacy), and the engineering costs (the reason IPv6 is still not dominant despite being "in the works" for 20 years now), because some future protocol which had not been shown useful over those 20 years ("research papers waiting to be implemented"). There is enough IPv6 to make the case for the need, and the ONLY case that has been made is "we're running out of IPv4" which is not wrong, but far from dire as I can still get 100 IPv4 addresses for $50, which is the same price I've paid for it 10 years ago.

Are you familiar of an ISP that will give you a new v6 prefix on demand (say, once every hour or day or week?) Or one that mixes all customers? otherwise, the NAT you do on your own behind that prefix is of very little (though not strictly zero) practical use; It just means that if someone gets access logs from two websites, they don't know if two requests were made from my laptop or one was from mine and the other from my kids.

I am not living in the US these days and have no knowledge on which to base the estimate ... but I haven't received an AAAA DNS record to any request I've made through several countries.

edit: added: My specific browser setup, described somewhere else around here, makes it hard to track or fingerprint. IPv6 takes that ability away from me (and everyone else).

>It is literally and has always been the software-defined network you use for interconnecting networks that have gotten too big. But the problem is, it was always too hard to hardware accelerate, and anyway, it didn't get hardware accelerated, and configuring DHCP really is a huge pain, so network operators just learned how to bridge bigger and bigger things.

IP forwarding (longest prefix match) is more complicated than mac forwarding yes, but it has been done in hardware (ASICs, typically NPUs today) for a long time now. Operators (I assume ISPs) do not build large bridged networks as they need their networks to scale as they grow, or they will hit a breaking point where their network collapses. ISP's typically use centralised DHCP servers (as opposed to configuring their access routers) and configure their routers to use DHCP relay. DHCP server configuration is easily automated by just reading your IPAM data, it's a non-issue.

http://www.bbc.co.uk/news/technology-16721338 - something I remember from recent-ish history. That data is, of course, still passed to O2's partner organisations (which don't seem to actually be listed anywhere), and you have no control over it.

> I find it disingenuous that you completely dismiss the societal cost (privacy)

I don't. I think there's other, significantly better solutions for it. I don't think NAT provides reasonable privacy in and of itself.

> the engineering costs

In practice, the fact that it's been spread out over 20 years so far is because that's how long it takes to get round to replacing an entire nation-wide deployment of carrier-grade infrastructure at all unless there's other reasons to do so. Smaller/regional ISPs have been on IPv6 for years now, partially because buying enough IPv4 space would be prohibitively expensive and partially because there's no reason not to. The technical details of IPv6 support were resolved in pretty much all networking kit a long, long time ago - it's a marginal cost at this point. The rest of it is primarily planning, testing, and replacing ancient consumer routers.

> the ONLY case that has been made is "we're running out of IPv4" which is not wrong, but far from dire as I can still get 100 IPv4 addresses for $50, which is the same price I've paid for it 10 years ago

And yet I can't get a real IP address for most of the things I'd like to. My ISP tries its hardest not to sell IPv4 addresses to anyone (it can't buy them quickly enough, and buying them is a huge resource drain - they lose money on every address sold, which is then made back up in subscription costs), let alone "home" users. On the other hand, it literally gives out static IPv6 ranges if you ask nicely.