This is the status of fibTmuPortsAllowedAddr. When reading, the possible values are as follows: addr-not-loaded indicates the value in fibTmuPortsAllowedAddr is meaningless. No security address has been loaded for this port. loaded-not-active indicates the value in fibTmuPortsAllowedAddr is stored in non volatile memory but security action for this port is not active. This happens when address is loaded while security action for the Tmu system is disabled (fibTmuSecurityModeRun has bit0 reset). loaded-and-active indicates the value in fibTmuPortsAllowedAddr is loaded in non volatile memory and security is active on this port. This means that if a station is directly connected to this port then it must have the specified physical address or this port will automatically close. As for writing, this object can be written only if its value is either 'loaded-not-active' or 'loaded-and-active' and the only value allowed is addr-not-loaded. In that case, 'fibTmuPortsAllowedAddr' is erased from the non-volatile memory and 'fibTmuNumStationLeft' is incremented. If port has been closed because of security (fibTmuPortsPortStatus had bit9 set) then it will open (provided it has not been closed because of some other reason).