Problem Statement: With the free flow of routing data and the high availability of computer resources, possible threats to the networks can result in loss of privacy and in malicious use of information or resources that can eventually lead to large monetary losses. Approach: MD5 Authentication: Due to the major role that routing protocols play in computer network infrastructures, special cares has been given to routing protocols with built-in security constraints using authentication techniques, MD5 will be presented for this work. Results: The study evaluates the impact of the MD5 authentication on routing traffic for the case of EIGRP, RIPv2 and OSPF routing protocols in case of secured and non-secured routing traffic and measures the delay time, jitter and overhead. Conclusions: This study shows 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.