@thecreativeone91 said:
I really think IPv6 only WANs are much further off than people keep saying,
I agree, but I limit that view to the west, because there are places in the world where they're becoming the norm. I think the future is actually set to have both, together, for a very long time. My guess is that American ISPs will start charging more for IPv4 addresses and nothing at all (aside from the service itself) for IPv6 addresses. This model is already in use around the world, and works out well.
partially because they've been saying that for years and years.
Imagine how I feel, I've been promoting and working with IPv6 since about 2001. It's been a long road. To give myself credit though, I was never one of those "we're gonna run out tomorrow" people or "transition is coming very soon," my thoughts were always "this is going to take a while and ISPs and IT departments are going to try to really push it off as long as possible, to the point where it's painful."
And the other thing is with most connections being Dynamic IPs they aren't as limited on IPv4 as the can recycle the addresses (and do, especially DSL connections which may drop with no traffic).
This is true, however even now some ISPs are coming up fantastically short and actually about 2 years ago Cox Communications went through a huge renumbering campaign with business customers in order to lower the total amount of allocated addresses. I imagine this bought them a few extra years. Another thing that can be done, and is typically done already, is that if a customer is dynamic, it will fail over to NAT (which you wrote about in your post as well). I've seen this happen before, where you receive an internal address from your ISP. You can still get online, however, you're behind their NAT. This is also in use in places where IPv4 addresses are extremely limited; America has more than anyone.
Dropping off inactive customers is another stop gap solution, however with the rise of cellphones and other internet devices, especially with streaming, this won't last forever.
If you combine ISP-level NAT, dropping off inactive devices, etc, you still only get a small window, there is the overall technical limitation of IPv4 in of itself. These are all temporary solutions.
I have setup IPv4 LANs with IPv6 WANs before as some gear needed wasn't compatible with IPv6, and they didn't wish to upgrade. Many routers will support this using a NAT64/NAT46 with a tunnel. Not something I recommend but can be done.
NAT64/46 is pretty much a thing that shouldn't be done, I agree, if anything people should be multistack if they are trying to coexist.
I'm totally in favour of people transitioning to using IPv6 and IPv4, so that in 5 to 10 years, probably closer to 10, as western ISPs start to catch up with the rest of the world (this is typical, as by the time most Europeans were using DSL, most Americans still had dial up for many more years) people won't scramble to update their networks. I think though the transition will likely be less of a big deal than other historical ones, because since people are moving more "to the cloud" and web apps, and so on, there's less need for crappy software companies to fix their issues, though a lot of people will still be stuck with old stuff that can't be fixed or was created by a company which refuses to fix it (essentially most niche software companies are like this) and it's good there's things like NAT46.
The point of my post above on the issue though was that the desire to rid a network of IPv6 instead of being multistack, I think is a mistake and instead American IT people need to learn to work with it and get used to the idea of it existing, so they're not left behind, as usual.