An information processing method executed by an information processing device, the information processing device being connected to a network, the network being connected to a first gateway, a second gateway, and at least one electronic control unit, the information processing method comprising:
- transmitting and receiving communication data through the network;
- determining whether the communication data is normal;
- transmitting, at least to the second gateway, a first notification to cause a first one of a transfer function of the first gateway and a transfer function of the second gateway to be active and a second one of the transfer function of the first gateway and the transfer function of the second gateway to be inactive, when the communication data is determined as not being normal in the determining;
- and
- when determining that the communication data is not normal in a case where the transfer function of the first gateway is active and the transfer function of the second gateway is inactive, (i) causing the second gateway to transmit, to the first gateway, a second notification to disable the transfer function of the first gateway and (ii) transmitting, to the second gateway, a third notification to enable the transfer function of the second gateway.