A method of determining a target path according to a source electronic control unit (ECU) mounted on a vehicle is provided. The method includes obtaining state information of a plurality of paths connecting the source ECU with a destination ECU, selecting the target path for target data from among the plurality of paths based on the state information, and transmitting the target data to the destination ECU through an ECU located on the selected target path, the state information including information about at least one of power consumption of an ECU located on the paths, a temperature of the ECU located on the paths, a latency of the paths, and a transmission success rate of the paths.