In the twenty-first century, the Internet of Things (IoT) is becoming an essential part of our day-to-day lifestyle. Therefore, it is important to do some research on a framework that provides key features of security, namely, privacy, availability, and integrity as well as something else such as authentication flexibility and robustness to deal with cyber-attacks. With the increasing complexity of network configuration and management, software-defined network (SDN) has become a promising and emerging technology used in the current scenario. In SDN, the brain is located in the control plane which is a layer of the SDN controller that allows administrators to dynamically design, manage, secure, and optimize network resources even when IoT devices are embedded with it. Despite the benefits of SDN, it has introduced some security loopholes which is the cause of being centralized. To improve and enhance the protection of confidentiality and other security aspects of IoT, the “BLEDGE-SDN” framework, i.e., distributed block chain integrated with Edge cloud in the SDN environment collectively comes out with a sustainable solution. In this paper, we compare earlier proposed framework and methodologies and study our proposed architecture which would be effective and efficient in real-time IoT network management along with threat identification and its mitigation. Resulting IoT devices are more secure for end-to-end communication and more protected from controller and DDOS kind of severe cyber-attacks.