Software Defined Networking (SDN),is an archetype which decouples the control plane and data plane. Data plane is used to just forward the data and control plane is used to decide how data should be forwarded. Open networking Foundation (ONF) is a group that is used in the development of SDN. For interfacing of control plane and data plane in SDN requires some protocol. One such protocol is Open Flow. The first standard interface designed for SDN is Open Flow. It provides high-performance, controlling granular traffic across multiple vendor's network devices. As the network infrastructure of an organization grows, it's very difficult to manage and control such networks from a centralized system like laptop through programs. As an attempt in this paper we are adopting the SDN technology to manage and control the networks programmatically. In this paper we are addressing the two issues for providing security to the network from DDoS mitigation and balancing of the load using SDN. In this paper for DDoS mitigation we are assigning a threshold value so that the SDN controller resists the DDoS attack programmatically. For Load balancing is to maximize throughput, minimizes response time, avoid overload by using round robin or random policy method using a new approach called SDN.