A method and a device for operating an electronic data-distribution control unit for a media access to a medium for the transmission of data, data being transmitted from a first physical interface for a first port in the data-distribution control unit to a second physical interface for a second port in the data-distribution control unit via a first media-independent interface between a media access control in the data-distribution control unit and the first physical interface and via a second media-independent interface between the media access control and the second physical interface, a case of a fault in the media access control being detected if a communication between the media access control and a monitoring logic in the data-distribution control unit fails, the monitoring logic, in the case of a fault, configuring the first physical interface and the second physical interface to transmit data via a third media-independent interface between the first physical interface and the second physical interface, without the media access control.