This object is used to configure and report whether or not this interface is operating in master mode. In a Demand Priority network, end node interfaces typically operate in slave mode, while switch interfaces may control the Demand Priority protocol and operate in master mode. This object may be implemented as a read-only object by those agents and interfaces that do not implement software control of master mode. In particular, interfaces that cannot operate in master mode, and interfaces on which master mode is controlled by a pushbutton on the device, should implement this object read-only. Some interfaces do not require network management configuration of this feature and can autosense whether to use master mode or slave mode. The value 'learn' is used for that purpose. While autosense is taking place, the value 'learn' is returned. A network management operation which modifies the value of dot12ControlMode causes the interface to retrain.