Tell HN: IPv6-only still pretty much unusable

Our Hosting provider, Hetzner, has recently started charging for public IPv4 addresses - as they should! Those numbers started getting expensive. This prompted me to try and set up a new server cluster using IPv6 exclusively, and see how far I could get before having to give in and purchase an additional v4 address.

The experiment ended much sooner than I had anticipated. Some of the road blocks I hit along the way:

  - The GitHub API and its code load endpoints are not reachable via IPv6, making it impossible to download release artefacts from many projects, lots of which distribute their software via GitHub exclusively (Prometheus for instance).
  - The default Ubuntu key servers aren't reachable via IPv6, making it difficult to install packages from third-party registries, such as Docker or Grafana. While debugging, I noticed huge swaths of the GPG infrastructure are defunct: There aren't many key servers left at all, and the only one I found actually working via IPv6 was pgpkeys.eu.
  - BitBucket cannot deploy to IPv6 hosts, as pipelines don't support IPv6 at all. You can self-host a pipeline runner and connect to it via v6, BUT it needs to have a dual stack - otherwise the runner won't start.
  - Hetzner itself doesn't even provide their own API via IPv6 (which we talk to for in-cluster service discovery. Oh, the irony.

It seems IPv6 is still not viable, more than a decade after launch. Do you use it in production? If so, how? What issues did you hit?

Hetzner should provide free CGNAT IPv4 Addresses (IPv4 Gateway) for IPv6-Only VMs

> Most ISPs, especially on mobile, have it now or are adding it very soon.

Except Charter/Spectrum in the US.

Just to specify the kind of "should": But they don't, do they? Same with vultr, their ipv6 boxes have no outgoing IPv4 connection route.

It's been a quarter of a century since IPv6 launch.

There's some really good lessons learned here. IPv6 requires everyone, everywhere, needs to change their configuration to add IPv6 addresses and network connectivity to every node/endpoint. The madness of course is that all the underlying infrastructure software (routers, OS, standard libraries) all support IPv6. It would seem, at a large enough scale, that software is the easy part, configuration is the hard part.

DJB wrote this up two decades ago[0] and it remains relevant. In particular the comparison between IPv6 and MX records. It took me a little while to wrap my brain around just extending existing software to support sometimes 32bit and sometimes 128. Ultimately it wasn't hard to dream up a few solutions for how that would work.

The other thing, FWIW, which has been slowing IPv6 adoption is business owners not asking for it as a high priority item from their providers. I've seen this happen way more often that I would like where provider asks a customer what they want and the customer never mentions IPv6, and when prompted shrugs it off because they don't see it as a business critical (and in fairness, it hasn't been). Yes provider isn't asking the 'nerds' at their customer's businesses, but those folks also aren't the ones paying the bills so...

0: https://cr.yp.to/djbdns/ipv6mess.html