I am trying to renew certificate but get timeout error. I checked availability of ports 80 and 443 from Port Checker - Check Open Ports Online, and website seems reachable in Website Uptime Test: Check Website Status | Uptrends. But http-01 challenge is failing. During the challenge I tried curl http://air.cs.itu.edu.tr/.well-known/acme-challenge/4cYht4W9exJbmOib2GwxKnUpPV2EYxrpyB8ZdMSGLvQ from another server (outside of this domain) and I can read the file. I currently disabled https redirection to test if this is the issue but it seems not.
My domain is: air.cs.itu.edu.tr
I ran this command: sudo certbot renew --apache -vv --debug-challenges
It produced this output:
The following errors were reported by the server:
Detail: 220.127.116.11: Fetching
Timeout after connect (your server may be slow or overloaded)
To fix these errors, please make sure that your domain name was
entered correctly and the DNS A/AAAA record(s) for that domain
contain(s) the right IP address. Additionally, please check that
your computer has a publicly routable IP address and that no
firewalls are preventing the server from communicating with the
client. If you're using the webroot plugin, you should also verify
that you are serving files from the webroot path you provided.
My web server is (include version): Apache/2.4.29 (Ubuntu)
The operating system my web server runs on is (include version): Ubuntu 18.04
My hosting provider, if applicable, is:
I can login to a root shell on my machine (yes or no, or I don't know): yes
I'm using a control panel to manage my site (no, or provide the name and version of the control panel): no
The version of my client is (e.g. output of
certbot --version or
certbot-auto --version if you're using Certbot): certbot 0.27.0
I also checked information on https://check-your-website.server-daten.de/?q=air.cs.itu.edu.tr, but not sure which ones are related to problem, can not using IPv6 cause a problem? Thanks for your help.