Provided is an in-vehicle network equipped with a function whereby configuration verification is performed while preventing an increase in the processing load (and cost) for each in-vehicle control device, thus improving vehicle security. This in-vehicle network system is equipped with a configuration management device that authenticates an in-vehicle control device. The configuration management device delivers to the in-vehicle control device, via a registration device connected to the in-vehicle network, configuration verification data that is used to perform configuration verification (see FIG. 1).