this object define 3 grades of port security: violation-protect(1): normal security grade, indicate that when the a datagram received on a port with illegal MAC address will be discarded but not send trap, legal and illegal MAC to a port security is defined by per port's security below. violation-restrict(2): normal security grade, indicate that when the a datagram received on a port with illegal MAC address will be discarded and send trap, legal and illegal MAC to a port security is defined by per port's security below. violation-shutdown(3): strict security grade, indicate that when the a datagram received on a port with illegal MAC address, the port will be disabled for the violation of the port's security and send trap.