A method for configuring a network element of a software-defined network “SDN” includes retrieving (401), for different look-up tables, a look-up table specific resource consumption estimate indicating a load factor of at least one component of the network element when running operations related to the look-up table, determining (402), on the basis of the look-up table specific resource consumption estimates, a resource consumption estimate for at least one look-up system including one or more of the look-up tables and having functionality suitable for the network element, and sending (404) to the network element, if the network element is capable (403) of running the look-up system, configuration data defining the look-up system. The method provides a possibility to avoid configuring network elements to overload and, on the other hand, the resource consumption estimates related to different network elements can be used for optimizing the software-defined network as a whole.