In-vehicle communication system and in-vehicle relay apparatus

Abstract

An in-vehicle communication system and an in-vehicle relay apparatus that can perform relaying between multiple in-vehicle networks if a new in-vehicle device is connected to a said in-vehicle network, and that can prevent, if an improper in-vehicle device is connected to the in-vehicle network, the entire system from being adversely affected by the improper in-vehicle device. The in-vehicle relay apparatus that relays information between the multiple in-vehicle networks has stored therein relay destination determination information necessary to determine a relay destination of information. If a new in-vehicle device is connected to any one of the in-vehicle networks, an acquiring unit communicates with a communication device to obtain updated relay destination determination information, a determination unit determines if the updated relay destination determination information is legitimate, and an updating unit updates the relay destination determination information of the in-vehicle relay apparatus.