An information processing device connected to a network, comprising: a communication unit (25,27) for communicating with each device on a network, determining whether to accept data received from a device on the network or not based on a prescribed criterion, and transferring the received data to the inside of the information processing device in response to the received data being determined to be accepted based on the prescribed criterion, characterized in that the device further comprises: a setting change unit for making a setting change to the prescribed criterion of the communication unit (25,27) according to instructions represented by setting request data in response to receipt of the setting request data requesting for the setting change of the prescribed criterion from a device on the network via the communication unit (25,27); a judgment unit for judging whether or not, having made the setting change by the setting change unit according to the setting request data, communication can be performed normally via the communication unit (25,27) with the device as the sender of the setting request data; a setting restoration unit for restoring the criterion set for the communication unit (25,27) before the setting change by the setting change unit in response to the judgment unit judging that the communication with the device as the sender of the setting request data can not be performed normally via the communication unit (25,27); wherein the judgment unit is configured to judge that the communication with the device as the sender of the setting request data can be performed normally via the communication unit (25,27) in response to data being received from the device via the communication unit within a prescribed time period from the setting change by the setting change unit and to judge that the communication with the device cannot be performed normally via the communication unit (25,27) in response to data can not being received from the device via the communication unit (25,27) within the prescribed time period. a communication unit (25,27) for communicating with each device on a network, determining whether to accept data received from a device on the network or not based on a prescribed criterion, and transferring the received data to the inside of the information processing device in response to the received data being determined to be accepted based on the prescribed criterion, characterized in that the device further comprises: a setting change unit for making a setting change to the prescribed criterion of the communication unit (25,27) according to instructions represented by setting request data in response to receipt of the setting request data requesting for the setting change of the prescribed criterion from a device on the network via the communication unit (25,27); a judgment unit for judging whether or not, having made the setting change by the setting change unit according to the setting request data, communication can be performed normally via the communication unit (25,27) with the device as the sender of the setting request data; a setting restoration unit for restoring the criterion set for the communication unit (25,27) before the setting change by the setting change unit in response to the judgment unit judging that the communication with the device as the sender of the setting request data can not be performed normally via the communication unit (25,27); wherein the judgment unit is configured to judge that the communication with the device as the sender of the setting request data can be performed normally via the communication unit (25,27) in response to data being received from the device via the communication unit within a prescribed time period from the setting change by the setting change unit and to judge that the communication with the device cannot be performed normally via the communication unit (25,27) in response to data can not being received from the device via the communication unit (25,27) within the prescribed time period. a setting change unit for making a setting change to the prescribed criterion of the communication unit (25,27) according to instructions represented by setting request data in response to receipt of the setting request data requesting for the setting change of the prescribed criterion from a device on the network via the communication unit (25,27); a judgment unit for judging whether or not, having made the setting change by the setting change unit according to the setting request data, communication can be performed normally via the communication unit (25,27) with the device as the sender of the setting request data; a setting restoration unit for restoring the criterion set for the communication unit (25,27) before the setting change by the setting change unit in response to the judgment unit judging that the communication with the device as the sender of the setting request data can not be performed normally via the communication unit (25,27); wherein the judgment unit is configured to judge that the communication with the device as the sender of the setting request data can be performed normally via the communication unit (25,27) in response to data being received from the device via the communication unit within a prescribed time period from the setting change by the setting change unit and to judge that the communication with the device cannot be performed normally via the communication unit (25,27) in response to data can not being received from the device via the communication unit (25,27) within the prescribed time period.