On my OPNSense system I use Unbound and Caddy.
With the help of Caddy, I access the OPNSense WebGUI from a PC on my LAN interface via https.
I was trying to get something else working today, and disabled Unbound. Immediately upon doing that I was locked out of the OPNSense WebGUI.
I had to connect a keyboard and monitor to my OPNSense box and do a restore from a backup earlier in the day (when Unbound was enabled) to get WebGUI access back again.
Is this a known problem?
You won't have been locked out. You disabled the DNS resolver so whatever URL you were using to access the web GUI could not be resolved.
You should have been able to access the web GUI using the firewall IP address to enable unbound again.
It's one of the reasons I recommend external DNS servers. They have multiple ones for high availability and you won't run into resolving issues like these.
Only one DNS server that should act as an authoritative DNS server (and not just a forwarder) is kinda tricky.
Best practice is 2 DNS Servers per zone.
QuoteYou won't have been locked out. You disabled the DNS resolver so whatever URL you were using to access the web GUI could not be resolved.
You should have been able to access the web GUI using the firewall IP address to enable unbound again
Well I very much suspect you are right:
I was trying to access it via:
https://192.168.1.1when I should have been using:
https://192.168.1.1:8443