Now, I want to create a new SSL certificate for my Synology NAS. I've done this several times before using a Google domain without issues. However, I'm now getting an error message that asks me to check my IP address, reverse proxy rules, and firewall settings.
My NAS is accessible under nas.jeromehelzel.de, and the domain is registered with the INWX DynamicDNS service.
Those names have different IP addresses in the public DNS. Let's Encrypt will validate to the server indicated in the public DNS system. Usually you run the ACME Client program that requests the cert on the same machine as the IP for the domain requested.
I’ve made the following changes: Previously, I had a DynDNS entry for nas.jeromehelzel.de at INWX. I deleted that entry and set jeromehelzel.de as the sole DynDNS entry. Before this, none of the subdomains were working, but now they all resolve correctly, and I have full access. The only thing left is the SSL certificate, but I’m still encountering the same error. Do you have any idea what might be causing this?
Yes, I made a small mistake with the IP address configuration. As I mentioned earlier, everything is working now, including the subdomains. The only issue remaining is obtaining the SSL certificate for jeromehelzel.de via Let’s Encrypt. Ignore nas. I didn't use it anymore. Do you have any idea why this might still be failing?