For about 4 years I have considered IPv6 first and IPv4 second. If IPv6 has an issue, I consider the service down, not just half down or slightly non operational. If I call an ISP for an IPv6 issue, I say "internet is down" even if IPv4 is working.<p>This policy helped move things forward on the networks I worked on. Lately I did setup a business internet with SLA, I specifically told the ISP I would not accept the contract if the SLA did not mention IPv6 as required.<p>But it is still a lot of battle, where it should be the default.<p>Github not fully supporting IPv6 is a real shame and they should really move things forward to support it quickly.<p>Also, systems should not use IP addresses as a mean of security or authentication, it was a bad idea for IPv4, it is even a worst idea for IPv6. To give you an example of bad firewall behavior, I was checking my electric bill from the train, and suddenly my account got blocked, and it took me a lot of time and effort to fix (physical mail...). My IP changed while I was browsing a page and the firewall didn't like it.