After restarting OPNsense, especially after an update, nginx is not reachable via my IPv4 on port 443. It is however perfectly reachable in IPv6 on this same port.
Sometimes, a simple reboot and it starts again, other times, nothing to do for days, it does not come back.
I checked my rules in the firewall, they are common IPv4/IPv6 so it can't come from there. I moved the OPNsense GUI to another port to make sure there is no conflict with port 443.
Any idea where the problem could be coming from?
The webgui has also a redirect port that needs to be disabled to prevent it blocking port 80.
You could try it locally using curl so there is no networking involved. The nginx plugin does not bind to any interface - this way it prevents itself from getting in trouble with interface going up and down.
This option is already disabled in my settings. I am still looking for the reason for this random problem.
If it happens every few days I suspect a nginx (software itself) or FreeBSD bug. The plugin configures nginx to listen on 0.0.0.0 and :: to avoid such cases with interfaces going down and coming up again.
any clue in nginx error log?
Maybe. Usually the log is filled with access errors but may contain IO issues as well.