On August 21, my Yunohost server, which I keep in my house, started warning we that port 80 was inaccessible from the Internet. None of my sites use port 80, so everything kept working, but I was concerned because I knew that my Let’s Encrypt certificate would fail to automatically renew if I didn’t fix the problem. Canyouseeme.org confirmed that the port was inaccessible. Today, with this evening’s diagnostic report, my server’s warning was gone and Canyouseeme.org confirms that the port is accessible again. I’m pleasantly surprised, but baffled.
Has anyone else run into a similar problem? I am on a residential FiOS connection.
Some questions come to mind:
Do you have a static IP address from your ISP?
Dynamic DNS?
Have you verified the listening service is a box you own?
Is there a reverse proxy set up?
Checked the edge router logs to see if it rebooted recently and reloaded firewall rules?
What else sits between your router and the listening server?
This could be any number of things, maybe this will help point you in the right direction.