I am fully aware that the 192.168.x.x ip range is considered private. However, I have a public IP, and yes you can ping it and head to the nginx landing page to verify, in the 192.18.x.x range. I am assuming that Let's Encrypt refuses to recognize this IP as being valid/public and therefore outputs the error stated below. I have used 'dig' commands to verify that it's returning the right values. My hypothesis seems to be confirmed from the fact this website, that I found while looking through the forum, says my IP is a private IP: https://check-your-website.server-daten.de/?q=oracle-0.node.fewermc.tk
My domain is: oracle-0.node.fewermc.tk
I ran this command (with nginx stopped): certbot certonly --standalone -d oracle-0.node.fewermc.tk --test-cert --verbose
It produced this output: Detail: no valid A records found for oracle-0.node.fewermc.tk; no valid AAAA records found for oracle-0.node.fewermc.tk
My web server is (include version): N/A but the same result is produced under NGINX
The operating system my web server runs on is (include version): Ubuntu 20.04
My hosting provider, if applicable, is: Oracle
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, ssh only at the moment
The version of my client is (e.g. output of certbot --version or certbot-auto --version if you're using Certbot): certbot 0.40.0
Weird.. And the RFC doesn't seem to be updated by another RFC?
Currently, 192.18.0.0 - 192.18.194.255 is assigned to Oracle according to the whois.. 192.18.195.0/24 is assigned to some medical research company, 192.18.196.0 - 192.18.255.255 is again assigned to Oracle and 192.19.0.0/16 is assigned to "Avago Technologies U.S. Inc.".. So it seems it's not so private any more
Tagging @lestaff by/for (?) lack of a Boulder-dev specific group
I am amazed at the quick replies! Thank you so much! Thankfully, in this case waiting a week is probably fine since we are just using the VPS for internal testing and the service will only be made available to users in about a week or two.
You can imagine my confusion and frustration as I try creating a cert over and over, even using AAAA records to see if that would help it get through =P
Once again thank you so much for the help