Abstract: An SNMP agent device includes: a receiving unit configured to receive an SNMP configuration command from a manager device; a configuration processing unit configured to update, when the configuration command designates management information and a configuration value, the management information in the agent device by the configuration value; and a configuration history storage unit configured to store the configuration command, mapping the configuration to a pre-update value of the management information. When the configuration command designates undo, the configuration processing unit performs an undo process of returning the management information updated by a past configuration command to the value occurring before the update.