| 摘要 |
PROBLEM TO BE SOLVED: To provide a network monitoring device and network monitoring method capable of estimating presence/absence of a communication message causing abnormality of a network communication state in a network where communication messages based on a multi-master system such as a CAN protocol are transmitted/received.SOLUTION: A monitoring unit 22 monitors a communication state of a communication bus 15 to which a communication device for transmitting a communication message using a CAN protocol is connected. The monitoring unit 22 determines that abnormality occurs in a communication state of a monitored communication message, when a reception interval of the monitored communication message is shorter than an appropriate reception interval specified as a range including a transmission interval of the communication message; and determines that abnormality occurs in a communication state of another communication message except the monitored communication message, when the reception interval of the monitored communication message is longer than the appropriate reception interval. |
