Using the Internet without IPv4 connectivity

Slightly misleading title, this is more “getting to the IPv4 internet via an IPv6 tunnel through a VPS”. Also just called 4in6.

Interesting nonetheless!

We find at our ISP that if we break something with IPv4 we experience a very different type of support issue to if we break IPv6. Breaking v4 results in, broadly, a pretty hard “down” state. While folks are unhappy, it is at least simple. Breaking v6 results in weird, and a partial down, which manifests for the users as partial outages, slow starts due to fall back, etc. Especially if their gateways believe there is v6 when there isn’t.

Most ISPs still just block IPv6 altogether because most small businesses seem to try IPv6 once and then forget to eg update their AAAA records so to the user it looks like their favorite niche thing works when they're on <low quality ISP at friend's house/coffee shop> but not on the one they're paying for which creates problems.

It's kind of a weird issue, I don't know if there are nice solutions other than hoping IPv4 just goes away eventually. Happy eyeballs was supposed to solve this but often the problems manifest way up in the application layer and there's no general protocol for solving that without some kind of very leaky abstraction because the application can do anything.

The compromise I personally have to make things smooth is enabling ipv6 in the network and then disabling ipv6 DNS on all of my browsers which is pretty unsatisfying.