Just trying to make sure I have the setup correct on my pfSense box.This has a lot more permutations/combinations than you realize... Just the first step...
What vlan interface?? The TRANSIT interface doesn't have to be a VLAN on the PFSense side. How's pfSense connected to the TRANSIT interface? physical NIC, virtual NIC? How's the WAN terminated? To pfSense or to the layer 3 switch?
I was under the impression that you needed to create the Transit Vlan on the pfSense box as well (see below)
In my setup, the Transit VLAN is created via 2 physical nics forming a LAGG interface.
In my setup, WAN is terminated on a physical nic on the pfSense box I think.