I'm trying to understand what it means for users... Does it mean that some content will not load on websites, increasingly so in the upcoming year or so? Does it mean that certain CDNs or hostings will simply not connect? I already have experienced that with some websites on a system with no IPv4 support, where I could connect through Tor, but not through any normal browser, so I'm just wondering.
I suspect youre talking about IPv4 and IPv6 ok.
Essentially, there is no way to directly connect IPv4 network to IPv6 network unless there is someone (switch, routers,etc) who speaks both 'languages'.
All internet is based over IPv4, immediate change to IPv6 is impossible due to its hugeness. So IPv6 adoption must be done gradually. So, there is gonna be a period of transition and coexistence between 6 and 4. We already on this period of time and we should expect more IPv6 networks in the future.
For example, we need someone who translates our communication between our IPv4 only network and the IPv6-only destination website network. The translation can be done by your ISP, the destination's ISP or whoelse in between both of you.
So answering your questions:
Does it mean that some content will not load on websites?
IF your ISP, or destination ISP, or whoever in between does not deliver you any kind of translation than yes.
increasingly so in the upcoming year or so?
In general I'd say yes, for the same reason as last answer and because we expect greater use in IPv6 in the future.
Does it mean that certain CDNs or hostings will simply not connect?
Yes, no translation no deal.
During the experience you told, it seems like a Tor node did the job of translation IPv6 to IPv4 for your IPv6 only network.
Its worth noting that as IPv4 ran out, some ISPs still do not make good use of IPv6 and keep using bad IPv4 solutions such as Carrier Grade NAT (CGN) to aggregate more costumers on a single IPv4 address. It creates a lot of issues, the main one is for making it difficult for costumers to, for example, play certain kind of games or services that rely on port forwarding.
ARIN ran out of IPv4 addresses to supply to the carriers. There is a market for blocks of IPv4 addresses, but it is supply and demand driven. Since the supply is dwindling, and demand is unabated, the price will be going up.
Many carriers have a good supply of addresses, for now. Other began to use Carrier-Grade NAT (CGN) a while back, and most carriers will implement this in the future. Unfortunately, CGN can break some things for users of the Internet.
Most of the carriers are providing IPv6, too, and the ones that have not yet implemented it are busy doing so now. The complete Internet transition to IPv6 is many years away, but, even today, about half of the tabs in my browser are connected via IPv6.
RFC 7021, Assessing the Impact of Carrier-Grade NAT on Network Applications, discusses the implications of CGN on home networks, including several case studies of different scenarios.
For most people, this means nothing. Telcos still have alot of addresses (used, some even unused).
What happens, depends on the country and telco. Most probably outcome is, that the cheapest internet packages (for end users) will be behing carrier-grade NAT, and power-users will be able to pay a few $/€/... more to get a public IP. Since alot of users have no idea what a public IP is, they wont pay for it.
Service providers (CDN, etc.) will continue buying/renting IPs, like they've done until now... until the price gets too high.
As stated in the other answers many providers will implement some for of Carrier Grade NAT (CGN). So you share an IP address with several other users,. If these providers take care and don't overload their NATs you'll notice not much if you only use HTTP(S), SMTP, ... If he dose overload his CGN you can find an example how google maps looks like in this presentation.
Now we have to possibilities:
- Your provider only uses CGN
- Your provider uses a combination of CGN for IPv4 and also offers IPv6
If you are using some external service like VoIP, VPNs or computer games which only offer IPv4 you may / will have some significant performance degradation or no service at all (somewhere between "works", "works sometimes", "does not work").
If your provider supports IPv6 and you are using external service which use IPv6 and your provider also supports IPv6 everything should work as usual. There was a BLOG post by a big German VoIP provider complaining that many of the access provider where using this new IPv6 stuff and NAT'ing IPv4 so their VoIP product would fail. The solution was simple: Implement v6. But complaining seemed to be easier.
If your running some kind of service (NAS, SSH, ..) at home you'll most probably have ho IPv4 access when your provider uses CGN.
On the content side you'll have to be aware that not implementing IPv6 will hurt your customers as CGN and other transition mechanisms will increase IPv4 latency. See this talk on youtube.
That means that ISP will be on dificulty to expand services to users who needs communicate with its own IP, i guess.
Ex: You want to get a dedicated line with its own IP range and be on charge of that, on this way, and if we look that we ran out of IPv4, the expansion will be dificult. More, one users maybe want to connect also some devices, and not only one, and equipments configured with NAT, only could accepted a fixed number of devices peer IP pool configured, if you want to provide a acceptable QoS in your service.