In America I've never had a non-mobile ISP offer IPv6. At this point it would be best to recognize the sunk cost and give up on the migration. IPv6 will never reach the 100% needed to turn off IPv4.
As was predicted in 1994:
Furthermore, we note that, in all probability, there will be IPv4
hosts on the Internet effectively forever. IPng must provide
mechanisms to allow these hosts to communicate, even after IPng
has become the dominant network layer protocol in the Internet.
It was averted: how do you think we got several billion smartphones connected to the Internet? Do you think that would have been practicable without IPv6?
Comcast—not even mobile—had to move to IPv6 on their landline ISP business because they ran out of IPv4 addresses for TR-069: they were using multiple 10/8 networks in different regions NATed to hide them from each other. IPv4 became untenable.
Put another way, we can drop v6 completely and the Internet will still work. Obviously wouldn't work the other way around.
As for telco addressing handsets, they could use any addressing scheme to be honest. When people talk about averting address exhaustion, they're not talking about internal addressing of networks, different problem altogether.
This is factually difficult to support. (Sent from my iPad which doesn’t have an ipv4 address… to hacker news which has an ipv6 address)
Most people run dual stack and as $favoriteHost gets AAAA, their traffic moves over.
My broader point was that your use of overstatement and a false dichotomy isn't _helping_ us get to a world where IPv6 is dominant.
Given they made the transition to IPv6 on handsets, T-Mobile US, which has 140 million subscribers, would disagree:
* https://www.youtube.com/watch?v=d6oBCYHzrTA
> As for telco addressing handsets, they could use any addressing scheme to be honest. When people talk about averting address exhaustion, they're not talking about internal addressing of networks, different problem altogether.
I'm sure if T-Mobile US thought they could, they would have:
> T-Mobile in the United States was running out of IPv4 addresses and needed an IPv6 transition strategy. Their solution was 464XLAT and IPv6-only.
* https://www.internetsociety.org/deploy360/2014/case-study-t-...
Similarly Comcast rolled out IPv6 because they ran out of addresses for managing their CPE modems using TR-069: they were using 10/8 multiple times over, and it was too much of a hassle so they went to IPv6 (both internally and to their customers).
But you still haven't addressed my original point, how has IPv6 averted the impending (at the time) IP exhaustion problem? As I remember it, we were running out of IP addresses, then we did run out, and CGNAT helped extend the life of the Internet for people on IP, while v6 still remains an island that is optional and doesn't help alleviate any of the pain.
TL;DR: v6 is not fit for purpose.
I would argue that mobile usage is the primary way that many people access the Internet in their personal lives, as evidenced by fact that IPv6 usage goes up on weekends, when people are probably not browsing stuff on work laptops.
> But you still haven't addressed my original point, how has IPv6 averted the impending (at the time) IP exhaustion problem?
If T-Mobile US could not offload a lot of traffic to 'straight' IPv6 they'd need a lot more publicly accessible IPv4 addresses. As it stands now they can only have their IPv4 addresses assigned to CG-NAT boxes, but without IPv6 they'd have to have way more IPv4 to assign to handsets, or given handsets 10/8 or 100.64/10 and have may more IPv4 on their CG-NAT hardware. (They'd also need way beefier CG-NAT hardware to handle higher loads.)
See also for example Vodafone moving to IPv6 to deal with IPv4 address shortages:
* https://www.youtube.com/watch?v=3CzFkvJ2Kxs
Or how Sky wouldn't have been able to create a new ISP without it because of a lack of available IPv4:
Only because of NAT. Those cellular CGNATs are v6 on the inside but v4 on the outside (well also v6 but customers need the v4 more).
> At this point it would be best to recognize the sunk cost and give up on the migration.
That's a pretty wild thing to say in the comment section of an article about v6 reaching 50% eyeballs-side deployment.
If that’s not a failure I hate to see what is.
How would several billion smartphones be able to connect to the Internet without IPv6?
There isn't enough RFC 1918 (or 100.64.0.0/10) space for IPv4-only to be practical: Comcast—not even mobile—went to IPv6 because running their TR-069 management over multiple 10/8 became untenable.
IPv6 is making all sorts of things possible without most people realizing it.
And how would they have gotten first-hop connectivity without IPv6?
Comcast added IPv6 many years ago on their wired ISP side because they ran out of IPv4 for TR-069 management, and they had way fewer subscribers (at least at the time) than many mobile telcos.
And that half of the Internet is also some of the most bandwidth intensive stuff: Youtube, Netflix, Instagram. The CG-NAT hardware costs of streaming would be huge.
No reason you can’t carry IPv4 over any protocol you want. Multi tennant vxlans can carry whatever you want over your base network. Maybe an IPv6 underlay makes sense there, doesn’t really matter
Bear in mind we've never done a project of this complexity and scale before. I'm sure we all wish it had been faster, but how can you possibly evaluate whether this is a failure or not without knowing how long it normally takes?
> At this point it would be best to recognize the sunk cost and give up on the migration. IPv6 will never reach the 100% needed to turn off IPv4.
That was probably a reasonable take 15 years ago. But we're at 50% v6 globally, and the ISPs that are doing v6 + cgnat would not want to move all that v6 traffic to cgnat. v6 traffic is managed with stateless routing; cgnat is stateful and costly.
There are many lessons that can be learned, but v4 only is not the future. v6 only might never happen... people are going to keep running old software in emulation that will never support v6... But global routability of v4 will likely end one day. And I'd suspect the tail of the migration will be much shorter than the head was.
I think the future is bright and most problems will be solved by 2040, and almost all by 2050.