The latest tremendous growth in the Internet traffic has determined the entry into a new era of mega-data centers meant to deal with this explosion of data traffic. However, this big data with its dynamically changing traffic patterns and flows might result in degradations of the application performance eventually affecting the network operators' revenue. In this context, there is a need for an intelligent and efficient network management system that makes the best use of the available bisection bandwidth abundance to achieve high utilization and performance. This paper proposes OFLoad, an OpenFlow-based dynamic load balancing strategy for data center networks that enables the efficient use of the network resources capacity. A real experimental prototype is built and the proposed solution is compared against other solutions from the literature in terms of load-balancing. The aim of OFLoad is to enable the instant configuration of the network by making the best use of the available resources at the lowest cost and complexity.