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Comment by lxgr | Hacker News Reader

Even Amazon can't make every single ISP in the world provide IPv6 connectivity, which would be required to actually deprecate IPv4 on the server side (or at least at the load balancer or other type of HTTP reverse proxy).

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They should offer NAT64/DNS64 gateway. It would work like other gateways and give IPv4 access to IPv6 hosts. Would probably be expensive like the NAT Gateway.

Is the gateway described here: https://aws.amazon.com/blogs/aws/let-your-ipv6-only-workload... no longer available?

That's the wrong direction (IPv6 clients calling IPv4 services). That doesn't help you for running a service yourself.

You'll need something it you want to download files from Github, because for some stupid reason they still don't provide IPv6 services for cloning and such.

you can run an NLB that terminates v4 and forwards to v6 internally: https://aws.amazon.com/about-aws/whats-new/2020/11/network-l...

ELBs (Elastic Load Balancer) supported IPv6 termination since 2011.

It looks to be available, but (from the bottom of the article) "Regular NAT gateway charges may apply."

Yes the problem is NAT gateways are expensive, not free. AWS could easily run a "central" 6 to 4 in each region (not in your VPC), which the incremental cost of using would be near 0. Then you could use pure v6 (no IP charges). And actually be able to talk to things like github, stripe, apple, etc.

I didn't know about that.

Do you mean NAT46? NAT64 is for IPv6 clients to access IPv4 servers, no? And how would you assign, e.g., port 80 to more than one IPv6 IPs in the backend?

The other option are application-level proxies/load balancers etc., but that's not easy if you want to support all possible protocols.

I'm talking about IPv6-only instances needing to access IPv4. Github is the big example.

Network load balancers (NLB) are for other protocols.

Sure, but NAT64 is much easier than NAT46 or application-level load balancing. It’s probably been how most people in the world access the internet for a while, to say nothing about NAT44.

The "official" solution is SIIT-DC but it looks like AWS would prefer that you use ALBs.

TIL about SIIT-DC, thank you.

This still requires mapping tables similar to explicit port forwarding, and also does not help with e.g. a scenario where all hosts need a specific port (e.g. 443) to be v4 reachable, right?

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