Routing is the process of forwarding data across an inter-network from a designated source to a final destination. Along the way from source to destination, at least one
intermediate node is considered. Due to the major role that routing protocols play in computer network infrastructures, special cares have been given to routing protocols with built-in security constraints. In this thesis, we evaluate the impact of MD5 Authentication on routing traffic for the case of EIGRP, RIPv2 and OSPF routing protocols in case of secured and non-secured routing traffic. A network model of four Cisco routers has been employed and a traffic generation and analysis tools have been developed and used to generate traffic data and measure delay time, jitter and overhead. The results show that the average delay time and jitter in the secured MD5 case can become significantly larger when compared to the unsecured case even in steady state conditions. Also, the EIGRP protocol shows the minimum overhead even when the system is extremely overloaded