We aim at improving the state of the art in organizing multicast communication for data center networks. Our novel General Load Balancer (GLB) approach leverages the Software Defined Networking (SDN) technology for efficiently distributing the multicast flow table entries and traffic in the network, thus avoiding link congestion and switch overflow. We target the popular FatTree topology, for which we ensure the construction of optimal multicast trees in terms of bandwidth usage and multicast entries usage. Our experiments show significant improvements in network parameters, e. g., bandwidth usage per link, group table utilization, and packet loss, as compared to the related approaches, such as Shortest Path Trees (SPT) and Avalanche Routing Algorithm (AvRA).