Software-defined networking (SDN) has revolutionized network management by enabling automated network configuration. The SDN architecture consists of a centralized controller which governs the entire network operation. In a traditional Internet of Things (IoT) network, the routing configuration has to be manually performed if there exist any changes in the network condition. However, the SDN controller can overcome this issue by performing network configuration from a centralized remote location. Based on the network topologies, various SDN controllers can be used to perform the overall management tasks. It helps to optimize network responsiveness and scalability while alleviating bottlenecks. In this chapter, various traditional IoT topologies have been considered to analyze the performance of networks under SDN-based IoT domains where SDN controllers were installed. The study was conducted using a Mininet-Wi-Fi simulator. The performance metrics considered for the evaluation purpose were average round-trip time, latency, and throughput of the network.