Nowadays, routing protocols have become a crucial part of the modern communication networks. A routing protocol's responsibility lies in determining the way routers communicate with each other in order to forward any kind of packets, from a source to a destination, using the optimal path that would provide the most efficiency. There are many routing protocols out there today, some old and some new, but all are used for the same purpose. In general, to ideally select routes between any two nodes on a computer network and disseminate information. This paper takes into consideration four of such routing protocols (RIP, OSPF, IS-IS and EIGRP), expresses them and analyzes their way of operation. It also presents the results of a simulation, that took place for the sole purpose of studying the behavior of those four protocols, under the same circumstances, as well as the evaluation of the comparison with one another based on the results of the simulation.