<p>The Routing Protocol for Low-Power and Lossy Networks (RPL) is the de facto standard for routing in IoT-based wireless sensor networks. However, its default best parent selection mechanism, which repeatedly triggers the best parent and path metric function across all neighbors, often results in redundant evaluations, increased control overhead, and higher energy consumption especially in dense or dynamic networks. This paper proposes an optimized best parent selection strategy based on a static and dynamic parent evaluation mechanism. Our lightweight and non-intrusive solution selectively evaluates only the current preferred parent and a dynamic candidate triggered by specific network events such as DIO messages or link metric improvements, thereby avoiding unnecessary recomputations. Simulations conducted using the Cooja simulator across different network densities demonstrate the effectiveness of the proposed approach. On average, the method achieves an 65% reduction in parent switching, a 54% reduction in control traffic overhead, and a 66% improvement in energy efficiency. Additionally, it increases PDR up to 98.33% and reduces latency by more than 62%, all while minimizing redundant executions of best parent selection and path metric functions, and maintaining minimal protocol complexity compared to standard RPL. These results confirm that the proposed strategy significantly enhances RPL’s routing stability, energy efficiency, and communication performance, making it a more robust and adaptable solution for IoT and LLN environments.</p>