The problematic installation was a fully working system for several months, with LE certificates installed and working fine for 2 domains. I got an email notifiation of one about ready to expire. I tried the renewal command, and it won’t renew with this error:
Domain: dummy.com !
Detail: Failed to connect to 184.108.40.206:443 for TLS-SNI-01
After repeated failures I blew away the letsencrypt installation and re-installed and also deleted /etc/letsencrypt. Same exact problem.
Command line I am currently trying (with many, many variations):
After googling, I tried various solutions related to firewalls, etc. I have no problem telnetting to port 443 both from the local system and a remote system. So thats not it. Tried completely dropping the firewall, no go.
Thinking something changed with the Apache configuration, I tried a webroot install, and that fails too (different error … basically unable to create a file I think).
The system is Ubuntu 16.04 / Apache.