Wireless Sensor Networks (WSN) consists of sensor nodes that are limited in terms of energy, size, processing speed and memory. Routing in WSN demands quick and large data transfer uninterruptedly. Due to the dynamic nature of WSN, better bandwidth utilization and routing stability are essential. Depending on the network structure appropriate routing protocol is required. IPv6 Routing Protocol for LLN's (RPL) is a proactive routing protocol for Low power Lossy Networks (LLN's). Mobility, topology control and effective resource managements are still hard challenges for researchers. This paper provides an overview of recent advancements in RPL protocol that support mobility. Also, in addition to mobility, the bandwidth utilization and topology control are also highlighted. Finally, a comparative analysis for various protocols is presented.