IPv6 is retrocomputing. I don't know much about Warewulf.

Huh. Did not realize we'd given up on that. Did the industry just settle on IPv4 after all?

Really depends on who you ask. You still need v4 to be "globally reachable", but v6 is optional.

AWS seems to finally be feeling the pinch of IPv4 exhaustion and is pushing v6 support everywhere now, and starting to charge for v4.

Mobile networks already have, and many are natively IPv6, with NAT64/464XLAT or other tech for bridging to v4. Apple's App store requires apps to support IPv6-only networks.

CDNs and clouds etc mean that websites don't even really need to worry about their own IP allocation, and just let their provider figure out exposing things worldwide.

> Apple's App store requires apps to support IPv6-only networks.

I read that and thought "huh, is that recent?" and found posts that were 9 years old about it. I guess apps just have to work on an IPv6-only network but I'm honestly surprised my apps do. I don't test in IPv6, my home network has it disabled, most of my servers don't have anything for IPv6 that I know of. Odd.

If you use the official network API, don't go out of way to use the old one, any app should support IPv6.

As long as the the servers they talk to have v6 addresses. Or does Apple implement some DNS64+NAT64 / 464XLAT setup transparently in its OSes too?

I think Apple tests on "IPv6 Only" networks that have DNS64/NAT64 to reach v4 servers

They do implement a CLAT, both in iOS and macOS afaiu.

Tangential, will email host spam reputation rely on IPv4 scarcity forever?

For longer, I expect. For a long time email has been partially centralised so for most real people and a lot of systems mail goes out through a specific host (or small number of hosts) on the edge of their network or completely outside it (sending individuals sending via services like gmail, and systems using services like sendgrid, and so forth) so the need to push for IPv6 is less apparent for mail sending than a number of other things. There are orders of magnitude less hosts sending mail than, say, making HTTP(S) requests.