I'm not sure the question was answered..  I have this same question.  I was going to do some testing on it but thought maybe someone had an answer.   : If 2 ports are right next to each other on a switch but they both are on different VLANs. Both Route through the MX. If both are in port isolation mode. Can they talk to each other if they are not restricted through the MX? In other words does port isolation only work on the connected VLAN, or across VLANs? Use case.. I don't want clients on the same VLAN to talk to each other but if I put a printer on another vlan and allow access via routing through the MX to another vlan even if the ports are on the same switch will they be able to talk? ... View more