Inter-Vehicle Communication (IVC) is a promising technology for the next generation of automotive vehicles. Recent advancements in IVC enabled the use of a wide range of safety and infotainment applications. Due to the fact that practical experiments are often not feasible, simulation of network protocol behavior in VANET scenarios is strongly demanded to evaluate the applicability of developed applications. In this paper, we propose a ETSI complaint Geonetworking protocol layer on well known NCTUns simulation framework. We also discuss the implementation details of the Geonetworking protocol layer and evaluate the performance of our implementation. We tested our implementation for different simulation scenarios. A detailed discussion about the performance of our implementation is also given.