Monitoring apparatus, monitoring program, and monitoring method

A monitoring apparatus installed in a vehicle and communicably connected to a gateway, the gateway storing a configuration information of a vehicle-mounted ECU and transmitting an update program, the configuration information including a MAC address and an IP address, the monitoring apparatus monitors the gateway, the monitoring apparatus comprising:

• an Ethernet cable, the gateway and the monitoring apparatus are directly connected by the Ethernet cable;
• control unit configured to obtain a plurality of pieces of the configuration information of vehicle-mounted ECUs from the gateway;
• and
• a storage unit configured to store the obtained configuration information as a backup of configuration information stored when the gateway is in a normal state,
• wherein, if previously obtained first configuration information and most recently obtained second configuration information are different, the control unit determines that the gateway has been replaced and executes a predetermined processing, and
• the control unit obtains the first configuration information and the second configuration information in a period of time not including a point in time when the configuration information of the vehicle-mounted ECUs obtained by the gateway is stored, wherein when the first configuration information and the second configuration information are the same, the control unit determines the gateway was not replaced and when the first configuration information and the second configuration information are different, the control unit determines the gateway was replaced, wherein when the control unit determines that the gateway has been replaced the control unit transmits a signal to the gateway to prohibit program updating.