Dear @Mitch_Rapp ,

Mitch_Rapp wrote

I am trying to create a vlan connection between my Deco X90 Mesh system & pfsense using an TL-SG108E  switch, to isolate my wireless & IoT devices.

Is that possible? see attached diagrahm.  I am a newbie so I might need step by step. :-) 

Yes, this topology is possible, but the following points need to be noted.
1. All your Deco's need to be wired to the switch and three networks established.
2. All Deco's are set to AP mode.
3. As for the settings on the switch, you only need to refer to this FAQ for the settings, note that the port connected to the front-end pfsense is set to Tagged and the port connected to the Deco is set to Untagged.

Best Regards!

Dear @Mitch_Rapp ,

Mitch_Rapp wrote

1. "and three networks established." 

What components will comprise the the three networks? I've added a new diagram and labeled things to make it easier for you to comment.See attached. 

And, if the three VLAN networks isolate the Deco's, will they still be able to operate as mesh even in AP mode?

2. "port connected to Deco untagged"

Ports connected to all Deco's back-haul untagged, or just the main Deco ?

1. In this case, there would be no Mesh and it would just be a matter of using these Deco's as normal AP's.

2. The egress rules of all the network ports on the switch to which the Deco is connected need to be typed as Untagged.

Best Regards!