A data network management system includes a data network management apparatus; and plural data processing apparatuses installed in an installation area and configured to transmit data to the data network management apparatus. The plural data processing apparatuses transmit identification information thereof together with the processed data to the data network management apparatus. The data network management apparatus determines based on identification information of data processing apparatuses that have completed a given authentication test among the plural data processing apparatuses and the identification information obtained from the plural data processing apparatuses installed in the installation area, a first data processing apparatus from which the data is to be obtained among the plural data processing apparatuses.