Using the Internet without IPv4 connectivity

When my IPv4 died last time, I noticed it mostly because Github didn't work anymore. These days, most consumer websites just work on IPv6. That said, people whose routers were only provisioned IPv4 DNS servers did have a full outage.

If Microsoft would get off their incompetent assets already, my biggest concern would've been remembering the mDNS hostname I've assigned to my router so I could log in and see if IPv4 is back already.

I think it's because of all of those transition mechanisms and fallback code added over the years. IPv6 fails the same way IPv4 does, but because of the terrible bullshit ISPs do to IPv6 connections, you end up with tons of software triggering obscure timeouts and fallback mechanisms that lead to a system of almost working networking code.

If the absence of IPv6 would've been treated the same way absence of IPv4 is, troubleshooting would've become a lot clearer. In fact, it probably would've been easier because ISPs can't just ignore and disable ICMP on IPv6 so you can actually get a hunch where in the network the problem is rather than seeing traffic vanish into the void.

I have strong opinions about ipv4, especially since I'm forced to use an ipv4 isp. The lack of ipv6 adoption should be considered one of the great failures of tech. Who actually is responsible? Is it router manufacturers writing poor quality firmware, ipv4 advocates in leadership positions at isps, ipv4 address speculators, poor training of network engineers and tech support staff? I think we all need to have a much greater discussion with the internet at large and not just on isolated web posts and subreddits.

For comparison, the internet mostly transitioned off of TLS 1.0 just fine, why can't we do the same for transitioning off ipv4? Maybe AI powered proxies for legacy code perhaps?

Happy "customer" here. I've been using their free 6in4 tunnel through OpenBSD for about five years and have had no mentionable problems. I configure mine solely with OpenBSD's network interface files, e.g. /etc/hostname.gif0:

  tunnel  
  inet6  128 alias 
  !route -n add -inet6 default 

I use the connectivity to reach a cluster of VPSes in AWS deliberately set-up without public IPv4 addressing, which would otherwise represent a large part of the monthly costs because of buttholes like Jeff Bezos actively monetizing IPv4 address space.

I don't think moving off IPv4 is on anyone's radar yet, unless you're buying VPS services that often come with a discount when you run on IPv6 only. In practice, you'll probably always have IPv4 connectivity of some sort, even though it's probably going to become more and more likely that that connectivity is attained through CGNAT.

Github is especially infuriating. For a few weeks, they ran a test, everything seemed to work great, and then they reverted to IPv4-only again.

Email servers live a decade or two in the past anyway. Disabling SSL 3.0 or TLS 1.0 support on email servers is still something you can't do without risking email deliverability problems. Microsoft Outlook's support and spam filters don't even seem to be aware of IPv6 capable mail servers (despite their headers showing they've been using IPv6 internally for ages).

I do wish IPv6 would be leveraged more, but the fear that maybe things work slightly less well for a minority of customers seems to be freezing every attempt at actually making use of the tech.

The reason you may be seeing weird IP behaviour from mobile carriers probably has to do with the way IP on mobile networks works, though. If you're on a call driving down a highway or sitting in a high-speed train, your phone will be doing handovers over and over again, and your IP address needs some form of stability. You may even cross a border and switch to a foreign network and the entire stack is supposed to maintain a seamless connection. There are special routing systems set up within cellular networks (some of which make excellent use of IPv6 features) that will make it very difficult to provide "normal" static GUAs to cell phones. Things are made as normal as possible, but it's not as easy to accomplish that kind of stability as you would with a fixed-line home internet connection.