Captive Portal behind existing firewall

[PD]

I already have a wired and wireless LAN network behind a firewall.

wired devices –----------------------------------------[ switch ] –----- [firewall] –--- internet
                                                                                |
                                                                                |
wireless devices --- [access points] –---------------------

i want to force all connected devices (wired and wireless) to go through a captive portal. How can I achieve that using PFSense?

My initial thought is I will need to put PFSense between switch and firewall. But, I am not sure how to configure PFSense to do that. I don't want PFSense to perform NAT or DHCP, want to only use its captive portal functionality. Any pointers will be appreciated.

[ozlecz]

activate captive portal on the firewall port (assumed pfsense based) where the switch is connected.

HTH