IPv6 Isn't Hard, It's Just Different: A GitHub Case Study

A Mastodon post lamented the difficulty of IPv6 configuration. The author uses GitHub as an example to show that the problem isn't IPv6 itself, but inadequate configuration and monitoring. Many websites, while having IPv6 address records (AAAA), are actually inaccessible via IPv6 because the browser's Happy Eyeballs mechanism prioritizes faster IPv4. In one case, a customer's split VPN tunnel blocked IPv6 connections. In another, traceroute showed that IPv6 routing terminated earlier than IPv4, indicating a possible firewall rule or routing issue. The author concludes: take IPv6 seriously, or don't use it. Lack of IPv6 monitoring and automation makes problems difficult to detect and resolve.