help to set up Captive Portal for WireGuard VPN

[mb19]

Hello everybody!

I have an OPNsense server on a remote network and I'm trying to configure the Captive Portal.

My Opnsense version: OPNsense 25.7.6 (amd64)

The setup is as follows:

• Interface wg0 is configured for WireGuard.
• I have a WireGuard client configuration on my local machine that connects successfully.
• When I access http://192.168.45.1:8000 after connecting, I expect to see the Captive Portal login page, but instead I get an "Empty reply from server."

Details

The interface wg0 is up and active, with IP 10.20.0.1/24.


The firewall allows access to the portal:

root@opnsense:~ # pfctl -sr | grep 8000
pass in log quick on wg0 proto tcp from any to (self) port = 8000 flags S/SA keep state label "x"

WireGuard client it's correct, I think, (local and endpoint IPs)

The OPNsense GUI shows the Captive Portal zone enabled on the WireGuard interface.
However:
When I open the portal URL --> http://192.168.45.1:8000
 I get "Empty reply from server."
No logs are produced when restarting the Captive Portal.
The directory --> /var/etc/captiveportal   does not exist although I don't know if it should exist
Would appreciate guidance on how to make the Captive Portal actually start and serve content when accessed through the WireGuard interface.

[Betaleav]

It sounds like the Captive Portal service isn't binding correctly to the WireGuard interface. First, verify that the interface `wg0` is assigned under *Interfaces > Assignments* and enabled. Then, in *Services > Captive Portal*, confirm the zone explicitly includes `wg0` and that its IP (10.20.0.1) matches your WireGuard subnet. Restart both the Captive Portal and `lighttpd` services. Also, check `/var/log/system.log` for startup errors — missing `/var/etc/captiveportal` usually indicates the portal never initialized. Re-saving the zone often regenerates this directory and fixes binding issues.