Development in digital infrastructure have resulted in distributed denial of service attacks to become increasingly widespread and target large number of host machines in organizations, that crashes down access when requested by the user. Such attacks when deployed on a larger scale, can result in a wastage of time and resources. With increasing complexity, these attacks have become more sophisticated and complex, leading to the emergence that has led to the rise of several algorithms and tools, that uses SDN (Software-Defined Networking) networks, in the domain of network security. Through this paper, we have surveyed what is a DDoS attack, its different forms and the use of software-defined networking tools such as Mininet and HPE VAN SDN controller, to analyze some basic topologies. Four different topologies were created namely Single, Linear, Tree and Torus, and experiments were performed to analyze the flow of traffic in these topology networks. From these experiments performed, the ping statistics in terms of minimum, maximum, average and minimum deviation Round-Trip Time (RTT) in milliseconds were computed for each of the given topologies. The values obtained as ping statistics were tabulated and represented graphically. A visual analysis between number of nodes and average round-trip time for the three topologies were done graphically. We have compared and analyzed several open-source tools, on their basis of efficiency of detecting the attack. Apart from this, a study of several instances of DDoS attacks in organizations regarding the mitigations and step initiated to withstand the intensity of these attacks, has also been done.