I’m trying to setup a certificate for a domain through my Synology NAS.
The message I got is “Unable to connect to Let’s Encrypt. Domain name not valid.”
This domain is registered as Type A to my public IP Address, where the Synology is.
I have check my port 80 and 443 with https://canyouseeme.org and they are working fine.
I have check my domain with https://letsdebug.net and all OK as well.
The domain is accessible in http and https from inside and outside my network.
I can’t ping my domain from the Synology itself or for any computers on my network, I have timeout (because pinging itself? )
Could you please provide hint to help me on this?
I can provide the domain by private message if really needed.
Thanks a lot for your kind help!