That sysadmin really enjoyed working on silly programs in his free time, he even runs a few websites! Oftentimes, this sysadmin is fairly surprised he has a real job as a Systems Engineer/Web Developer.
This is one of those times.
I recently decided to switch my domains' name servers from CloudFlare to FastMail. There were a few reasons for this, all of which turned out to be the wrong answers to the original questions.
It all started when I had
mail.jrgnsn.net set to redirect to
fastmail.com. I kept getting Invalid Certificate errors since the
jrgnsn.net but the server is (and the certificate was for)
fastmail.com. I spent a good few months perplexed why there would be
an issue, "mail dot" all my other domains worked just fine, after all.
So I went ahead and switched name servers on all of my domains to FastMail's domain servers. This accomplishes several things:
Unfortunately, all of the existing issues remained and I even added a
few issues to the list!
mail.jrgnsn.net was still returning
certificate errors. Additionally,
https://veganmsp.com wasn't being
resolved at all. dig-ing at
22.214.171.124 were all returning SERVFAIL for
This was frustrating to say the least, but I learned a valuable lesson throughout this process that I have yet to put into practice. Documentation is important.
I'll say it again, DOCUMENTATION IS IMPORTANT!
It turns out there was an HTTP Strict Transport Security (HSTS)
directive tucked neatly away in an Nginx snippet. I don't remember
putting it there, perhaps Ghost did that automatically when I upgraded.
After removing the HSTS directive and forcing Firefox to "Forget About
This Site", my
jrgnsn.net domain was behaving as expected!
veganmsp.com was still giving me trouble, though, and it was worse
jrgnsn.net. Certain DNS resolvers would return a
others would return
NOERROR with the correct values. I was baffled!
Why in the hell are some resolvers working while others, especially the
"big name" resolvers weren't?! Turns out the answer was simple and if I
weren't so curious, perhaps I could have avoided this issue altogether.
There was a DNSSEC record for veganmsp.com. 🙄
After some quick research, I learned one of the better methods to changing name servers with a DNSSEC record is to delete the record at the Registrar, wait 24 hours, delete the record at the name server, and then change name servers.
I changed name servers, was looking into this for a few days, and then deleted the record at the registrar.
At the time of this writing
126.96.36.199 still return
SERVFAIL. I'll give it 24-48 hours until I
continue the investigation.
And maybe I'll start a local wiki to keep domain, DNS, and security configurations in a central location.
How am I employed in this industry, again?