I received an email from you on March 3rd indicating that one of my domains (nthos.com) was affected by the recent bug you found. I renewed the certificate and then checked it using https://checkhost.unboundtest.com/. The response I got was:
I rechecked multiple times over an extended period, and always got the same response. Out of curiosity, I then checked all my other domains using the above URL and found that two more of them (nthos.net and nthos.org) got the same timeout response.
I then created new certificates for all three, but upon testing using the above URL, still get the timeout response.
What exactly is the tool checking, and should I be concerned about the response?
Thank you for your fast response and the link to your site, which is impressive and provides a great deal of useful information.
As soon as I looked at your site and thought about the fact that the three domains in question all share the same IP address, I realized what the problem was. I had been debugging some server-side issues and was looking at log files the same day the certificate problems surfaced.
There was so much unwanted traffic in the logs from people/bots sniffing for vulnerabilities that I restricted access in the firewall to a limited set of IPs. Unfortunately, I forgot to remove the restrictions when I was done! Too little sleep and too many distractions...
I sincerely apologize for wasting your time on this. But I am glad I learned about your site. I'm sure I will use it again in the future.