This read-only TruthValue reports whether the switch has taken control of a protocol-based filter row and its resources for an internal feature such as 802.1x authentication. Admins check this to understand why a configured protocol filter or VLAN classification rule isn't behaving as expected, since a preempted row's resources are being used by the switch rather than enforcing the admin's rule. If etsysESwitchProtocolPreempted reads true(1) for a vlan(2)-constrained row, the admin should expect 802.1x-driven VLAN assignment to override the configured etsysESwitchProtocolVlanId for that port.