In the near future, IP-based wireless sensor networks will play a key role in several application scenarios such as smart grid, smart home, healthcare, and building automation... An IPv6 routing protocol is expected to provide internet connectivity to any IP-based sensor node. In this paper, we propose IRPL protocol for IP-based wireless sensor networks. IRPL protocol uses a combination of two routing metrics that are the link quality and the remaining energy state of the preferred parent to select the optimal path. In IRPL protocol, we combine two metrics based on an alpha weight. IRPL protocol is implemented in ContikiOS and evaluated by using simulation and testbed experiments. The results show that IRPL protocol has achieved better network lifetime, data delivery ratio and energy balance compared to the traditional solution of RPL protocol.