A wireless sensor network is a group of network nodes which collaborate with each other in a sophisticated fashion. It is built of nodes from a few to several hundreds or even thousands, where each node is connected to one (or sometimes several) sensors. In WSN, Second layer of the OSI reference layer is a data link layer which has a sub layer of Medium Access Control. The choice of Medium Access Control (MAC) protocol has a direct bearing on the reliability and efficiency of network transmissions due to errors and interferences in wireless communications and to other challenges. They are primarily responsible for regulating access to the shared medium. There are a lot of protocols developed to protect from DOS attack, but it is not completely possible. One such DOS attack is vampire attacks which cause damage in network. Secure level is low; productivity reduces which leads to environmental disasters and cause loss in the information. Routing protocols play an important role in modern wireless communication networks. Hence propose Interior Gateway Routing Protocol (IGRP) where router used it to exchange routing data within an independent system. In WSN routing protocols find the route between nodes and ensure the consistent communication between the nodes in the network.