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Comment by lxgr | Hacker News Reader

> Because CGNAT is more prominent, and more heavily used, in Africa and Asia […]

Isn’t essentially the entire US on CG-NAT for IPv4 on mobile data?

I’ve also had DOCSIS connections, i.e., fixed lines, with only CG-NAT in Europe years ago.

I wonder if that's not very visible in Cloudflare's data because those mobile devices will likely use IPv6 to connect to Cloudflare-hosted sites.

That’s what I was thinking. Anyone coming from Cloudflare will end up getting there via IPv6.

I use cloudflare to make my weather station available over T-Mobile. They don’t filter inbound ipv6 on regular phone lines (they do for TMHI) so you can host a simple page on ipv6, only set the AAAA record in cloudflare, and they will proxy it for ipv4 users so I can ignore being CGNAT’d for ipv4. Make sure if you do this setup with a tool like ddclient to keep the record current as T-mobile rotates ipv6 frequently

Well, what I mean to say was “anyone coming from Verizon will get to Cloudflare via IPv6”.

My current endpoint lacks IPv6, so I use Cloudflare so IPv6 clients can get to it. Verizon’s IPv6 is noticeably faster than their IPv4 CG-NAT.

mobile devices dont get ip6 do they? last i looked my cheapo gateway only provided v4 cgnat

Phones have been on IPv6 for years.

> Isn’t essentially the entire US on CG-NAT for IPv4 on mobile data?

T-Mobile, for one, has had their handsets IPv6-only for a few years, so if your Android/iOS does a DNS lookup and gets an AAAA record back, it will skip CG-NAT. T-Mobile presenting at NANOG in 2018 on IPv6:

* https://www.youtube.com/watch?v=d6oBCYHzrTA

And Rocky Mountain IPv6 Taskforce in 2017:

* https://www.youtube.com/watch?v=nNMNglk_CvE

Further data:

> Chances are if you use the Internet on your smartphone, you are connecting via IPv6. According to the Internet Society’s 2018 State of IPv6 Deployment,[1] 80% of smartphones in the US on the major cellular network operators use IPv6 and major mobile networks are driving IPv6 adoption with Verizon Wireless at 84%, Sprint at 70%, T-Mobile USA at 93%, and AT&T Wireless at 57%. Plus, some mobile networks are taking the step to run IPv6-only to simplify network operations and reduce costs.

* https://www.arin.net/blog/2020/01/16/mobile-edge-of-the-inte...

Though some folks aren't happy with the implementation:

> But from my own experience, neither T-Mobile nor AT&T allows inbound traffic to the phone's IPv6 address. This negates some of the advantages of having a globally routable IPv6 address.

* https://isc.sans.edu/diary/27814

> Plus, some mobile networks are taking the step to run IPv6-only to simplify network operations and reduce costs.

I think this has also already happened. You don't really notice it as a user, because the phone itself can act as a 4-to-6 translator (similar to how DS-Lite in DOCSIS transports CG-NATted v4 traffic in v6) for both native apps doing incompatible things with literal v4 addresses and tethering clients.

In Brazil I think basically more than half of fixed broadband should be CGNAT.

Basically only one single ISP don't use CGNAT...

Would be interesting if Cloudflare could give this info!

For those of us who don't have many options other than satellite internet, it generally uses CG-NAT, specifically Starlink.

AFAIK all mobile networks use NAT unless you pay a lot more for a special service with a public static IP.

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