This read-write PortList specifies the set of ports belonging to a protected port group, meaning those ports cannot forward traffic directly to one another even though they can still reach uplink or unprotected ports. An administrator adds ports to this list to isolate end-user devices from each other while still allowing them access to shared resources like the internet gateway. For example, an admin protecting a bank of public-access kiosks would add all kiosk ports to ctAgentSwitchProtectedPortPortList so they can't see each other's traffic.