For conventional v6 routing, the upstream router (pfsense) needs to delegate a prefix (/62 or larger) to your OpenWrt router. Then OpenWrt uses a /64 block from that prefix for each LAN. If your ISP does not supply a suitably large routable GUA prefix you can use ULAs, which I think is what Matter typically expects.
The alternative is to set up the AP to bridge its multiple SSIDs directly into different VLANs on the Ethernet cable, configure the managed switch so they all trunk back to the pfsense router, and let that main router handle it all. This is an extension of the "dumb AP" concept to have more than one network, yet all of them are "dumbly" yet separately bridged out. It is merely a wireless to wired converter not doing any routing. A bridged AP operates at layer 2; it does not care if the layer 3 traffic is v4 or v6 or both.
That sounds like what I am attempting to do but I am lost in the weeds.
Below is the VLAN configuration on the 16 port switch.
VLAN ID VLAN Name Member Ports Tagged Ports Untagged Ports
1 Default 1-16 1-16
33 IoT-vm 1-2,9 1-2 9
LAN is 192.168.1.0/24
VLAN 33 is 192.168.5.0/24
Port 9 goes to a NIC on my VM host.
Port 2 goes to a WRT1900ac running OpenWrt.
The AP has been providing WiFi Internet access for devices in my home.
Now I would like to add a IoT SSID configured for VLAN 33.
Took a look at the Guest Wi-Fi link that @egc provided. My attempt to implement was unsuccessful as I attempted to modify to meet my requirements. Was able to connect to the IoT SSID BUT did not pass traffic.
Using pfSense as my router/firewall.
Any guidance you could offer would be most appreciated.
I am going to reread a few times what you posted in hopes that it will sink in.