As the movement for a vast implementation of IoT networks is rapidly accelerating, so many researchers are working to analyze the performance of RPL, the widely-used routing protocol for wireless sensor networks. The analysis usually involves a small number of metrics studied under a limited number of scenarios. In this paper however, we provide a comprehensive study for the performance of the two objective functions used in RPL; MRHOF and OF0, using the Cooja simulator in Contiki operating system. Using static-grid and mobile-random topologies with 25, 49, and 81 sender nodes including one sink node. Each topology was tested with three transmission ranges of 11, 20, and 50 meters to simulate sparse, moderate and dense networks. The selected metrics are convergence time, changes in DoDAG tree structures, average churn in the network, Average Power Consumption, Average Listen Duty Cycle, Average Transmit Duty Cycle, Average received packets, average lost packets, average duplicate packets, and average hop count. In fixed networks, the results show that OF0 usually perform better than MRHOF in terms of Energy Consumption, Convergence Time in the Static-Grid Topology, Listen Duty Cycle, and Transmit Duty Cycle.