A person installed Nextcloud 16 on an ubuntu 18.04 server for me. I am very new to all this, so I did not understand all that he did. (I am grateful for his help, though.)
I have an Asus RT-AC87R router. The ubuntu server uses this router. Before he did anything for me, long ago I used the router’s ddns functionality to create a url for my router: xxxx.asuscomm com . The router’s instructions said that Asus would maintain that as a dynamic URL – similar to what no-ip com does – and, the router would acquire and automatically renew a Let’s Encrypt certificate. This then allows me to access a hard drive attached directly to my router from anywhere just by using that URL. This has worked great for the past few years.
As part of the installation of Nextcloud, the person said if I want an SSL connection to Nextcloud, I need to create a dedicated, separate URL. So, at no-ip.com I set one up: zzzz.ddns net. When he was installing Nextcloud on my ubuntu server, I could see in the command lines that he was doing “something” with zzzz.ddns net, and he got a Let’s Encrypt certificate installed on the server, and he set up certbot. And it works, I can access my Nextcloud system from anywhere using zzzz.ddns net. However……
Now, when I try to access xxxx.asuscomm com, I am always directed to a page that gives this error message:
Your connection is not private
Attackers might be trying to steal your information from xxxx.asuscomm com (for example, passwords, messages, or credit cards). Learn more
This server could not prove that it is xxxx.asuscomm com; its security certificate is from zzzz.ddns net. This may be caused by a misconfiguration or an attacker intercepting your connection.
Proceed to xxxx.asuscomm com (unsafe)
And then, if I proceed anyway, I am sent to a Nextcloud page that says this:
Access through untrusted domain
Please contact your administrator. If you are an administrator, edit the “trusted_domains” setting in config/config.php like the example in config.sample.php.
Further information how to configure this can be found in the documentation.
So, now I am very, very confused.
Why and how would the set up of a no-ip.com URL and a Let’s Encrypt certificate on my ubuntu server have any impact on the ddns URL and Let’s Encrypt certificate that my router was managing?
I really don’t understand this stuff, and I don’t know how to proceed.