A software-defined network includes a database (105) that is accessible to a controller system (108, 109) of the software defined network and also to network elements (101-014) of the software defined network. The controller system determines configuration data and delivers it to the database. Each network element retrieves its part of the configuration data from the database and implements the retrieved part of the configuration data into its own configuration system that enables the network element to operate as a part of the software-defined network. The commonly used database facilitates maintaining the congruence between the network elements and the controller system of the software-defined network.