My old router start to fail and I replaced it with a mini PC running Opnsense.

I have the LAN output on the mini-PC connected to a switch which then connects to my Unraid Server and wireless access points.

Internet is working fine. Access Points are working fine. Unraid server is working fine (plex and other dockers are working and accessible if I directly put in the IP and port). My reverse proxy is working fine.

However, I cannot access the Unraid GUI. I get this.

I logged into Unraid server via Telnet (through PuTTY) and it seems to work fine. Ran the lscpu command and it brought up a bunch of details.

I'm at a loss at what to do. Normally I would download the diagnostic logs via the GUI.

I have been checking the OPNSense forums and researching but I don't think it's an issue with OPNSense considering the server is still working fine and I can access some of the dockers.

What have I done wrong?

EDIT:

1) I have tried tower.local and it goes to the same page linked above.

2) Is there a way to access the GUI by physically connecting to the server?

Edited August 10, 2025Aug 10 by bobalot

Type in the CLI use_ssl no then see if you can access using http://tower.local or the http://IP_address

3 minutes ago, JorgeB said:

Type in the CLI use_ssl no then see if you can access using http://tower.local or the http://IP_address

It worked! To avoid doing this in future, what did I do wrong?

Start by reading this:

Then this section of the manual:

https://docs.unraid.net/unraid-os/manual/security/secure-webgui-ssl/

If you pull the Flash drive, you can the setting for this variable in the /config/ident.cfg file.

USE_SSL="yes"

(I copied this from one of my ident.cfg file. You probably want to change it to "no"...)

13 minutes ago, Frank1940 said:

Start by reading this:

Then this section of the manual:

https://docs.unraid.net/unraid-os/manual/security/secure-webgui-ssl/

If you pull the Flash drive, you can the setting for this variable in the /config/ident.cfg file.

USE_SSL="yes"

(I copied this from one of my ident.cfg file. You probably want to change it to "no"...)

Thanks for that information. I managed to get access following JorgeB's advice above and turning off SSL.

Reading what you have posted, OPNSense does have DNS Rebinding protection (which can be turned off) which may have been causing the issue.

Wondering whether to turn SSL/TLS back on and turning off DNS Rebinding protection on OPNSense.

21 minutes ago, bobalot said:

Wondering whether to turn SSL/TLS back on and turning off DNS Rebinding protection on OPNSense.

I can't advise you on this. It is a choice you have to make. It is a security risk to turn it off. How big a one is a matter of debate. Most consumer routers have it off with no provision to even turn it on. If you look carefully at the instructions, some of the router only allow it for specified sites. Probably the best solution of providing function with security.

5 minutes ago, Frank1940 said:

I can't advise you on this. It is a choice you have to make. It is a security risk to turn it off. How big a one is a matter of debate. Most consumer routers have it off with no provision to even turn it on. If you look carefully at the instructions, some of the router only allow it for specified sites. Probably the best solution of providing function with security.

Fair point. I turned it back on and disabled DNS Rebinding Checks on the OPNSense router. Seems to have fixed the problem.