The Internet of Things (IoT) has rapidly grown to encompass billions of devices, creating a heterogeneous network with diverse underlying protocols, making it challenging to supervise and secure effectively. IoT devices often possess limited processing power and storage capacity, rendering them vulnerable to attacks, including Distributed Denial of Service (DDoS) attacks. Integrating comprehensive security features is a difficult difficulty since IoT devices have limited resources. In order to effectively identify and mitigate DDoS attacks, this research paper suggests a strategy that uses Software Defined Networks (SDN) as gateways for IoT networks. SDN provides network resource centralized control and programmability, solving the particular security problems faced by IoT. Centralized management, dynamic configuration, network isolation, and policy-based security enforcement are some of the benefits of SDN in IoT security. The advantages of our IoT framework built on SDN include: The IoT ecosystem's security and resilience against DDoS attacks will be improved through real-time traffic analysis for DDoS attack detection, automatic response mechanisms to counterattacks, and dynamic resource allocation to handle increased traffic during attacks.