During the last 36 hours some people had problems to reach Moon of Alabama.
The issue was weird. For some it worked on their phone and laptop but not on their tablet. Others had the opposite experience. I could not reproduce the problem on my machines.
It took a while to track this down but now the problem is solved.
For people with some Internet Protocol knowledge here is in short what had happened:
User device <—> Google DNS <—> Registrar DNS
The problem occurred only recently and only on devices configured to use Google's public Domain Name Servers. Google's DNS servers 8.8.8.8 and 8.8.4.4 responded to NSlookup requests for moonofalabama.org with 'failure'.
The reason for that turned out to be a weird error in the communication between Google's DNS and PAIRnic, the domain registrar for moonofalabama.org. When Google's DNS requested the IP4 address for the site from the registrar DNS everything went well. When Google requested the IP6 address for the site from the registrar DNS the request failed for all domain names at PAIRnic that are configured with DNSSEC enabled (which moonofalabama.org usually is). This happened only for IP6 request from Google's DNS, not for IP6 resolver requests from elsewhere.
The registrar now found a workaround that avoids the Google IP6 resolve problem.
Still, Google should have been able to deliver valid responses for IP4 resolver requests to it. But because the Google IP6 request to the registrar DNS failed, Google responded to both, IP4 and IP6 lookup requests for moonofalabama.org, with 'failure'. That behavior is somewhat unexpected and IMHO a bad implementation.
Anyway – you now know what I spent my day on and why there is no regular blog post.
Thanks to everyone who helped to solve this problem.