I have my Pi set up as an ownCloud server. I have port forwarding enabled on my router for two specific ports (one for SSH one for HTTPS), and the Pi is configured to accept these requests on these ports. Both of these services ran perfectly until a few months ago. Suddenly, I could not access the Pi externally, despite having made no changes to any Pi or router configurations. I have not had physical access to the Pi or router until now.
I can log into the Pi via SSH on the specified port from within my network. The issue now is that the logs in /var/log do not date back far enough to the time this issue began so I cannot view the auth, apache, sys, fail2ban, or user logs. When I connect to the Pi, I can confirm it has external access as I can ping google.com, curl icanhazip.com etc. with no issues.
Again, I did not change any settings on my router or Pi prior to this change occuring. I have since updated all packages in attempt to eradicate the error but it did not work. I am really lost. Can anyone provide me with some guidance?
Edit for clarification
When I try to access the machine via SSH using the domain name, the error I get is a timeout. When I ping the address of the domain name, I get the error "Destination host unreachable".
Interestingly, the public IP address listed when I ping the domain name of the Pi is not the same as the one provided when I run "curl icanhazip.com" while logged into the Pi. Using the IP address provided by icanhazip.com, I can succesfully log into the Pi remotely. Does this mean that my domain settings have been misconfigured somehow?
This issue is solely to do with my own carelessness in not renewing my domain name, not a result of misconfigurations, firewalls, port forwarding etc.