Given that there is some ridiculous number of IPv6 addresses per every single person on the planet, why do ISPs still charge for IPv4 addresses? Why not just give the user an IPv6 address?
Is it purely on the basis that a layman is not going understand this IP?
I read in my CCNA that IPv6 adoption in the mainstream is slow and usually limited to mobile devices. In my own personal opinion, progress seems throttled because companies still want to charge for IPs and don't want to address that there is no IP starvation in IPv6 (yet).
Best Answer
IPv4 and IPv6 are separate protocols. They can't inter work without some form of translation mechanism.
The original idea of the IPv6 proponents was that we would all move to dual stack running IPv4 and IPv6 in parallel. Then once everything was dual stack, IPv4 could be phased out.
The problem is that plan just isn't attractive from an economic perspective. The costs of going dual stack come immediately, but most of the benefits of IPv6 don't come until some unknown time in the future when IPv4 can be turned off.
The result is that IPv6 remained mostly a toy for techies for over a decade.
In the past few years as the availability of IPv4 worsens we have started to see a bunch more movement towards IPv6, usually in combination with some form of transition mechanism to allow access to resources on the IPv4 internet. Some large ISPs have gone down this route.
Right now though, there are still many v4 only client networks. So if you want to host services that are accessible from networks outside your control (either because they are accessible to the general public or because you have users "on the road" who need to access them) you need public v4 addresses.
It will be interesting to see how far IPv4 prices have to climb before IPv6 becomes ubiquitous.