@Gertjan said in Trouble With CaptivePortal on Two VLANs in One Interface: You are already using multiple interfaces - a VLAN is considered as a interface. Typically, each interface has its own dedicated AP(s) - using a dedicated radio (== Wifi) setup. A user should choose the correct Wifi SSID first to use the correct network. You can't automatize this. I just wanted to make it happen. I was planning to redirect the user to the correct VLAN by using just one SSID. But I completely got that I can not do it. Thanks for your helps. @free4 I still can not find an opportunity to try PacketFence. I will write down here if I can be successful on it.

Create a LAGG on pfsense and on the switch stack. Use the LAGG as the vlan parent.

Even better : access the console ! If memory serves me well, a Link Up (and down) event is signaled as soon as you hook up a cable - and unhook. It will mention which interface it is.