An information processing device which transmits and receives a message to which a communication ID indicating a class has been assigned, includes: a storage unit which stores, for each of the communication IDs, a communication counter for verifying a recency of a communication; a recency information management unit which updates the communication counter based on a predetermined condition; an abnormality monitoring unit which identifies an influence range of an abnormality that occurred; and a message generation unit which generates a synchronization request message including the communication ID indicating that it is a message requesting a synchronization of the communication counter, and a synchronization target identifier indicating the influence range identified by the abnormality monitoring unit.