Determining unwanted DHCP server on the campus networks withthe SDN

In recent years, the load on computer networks has increased with the integrated use of technology in different areas. The continuous growth of traditional computer networks by the addition logic has made the manageability of these networks difficult. The fact that the innovations in network devices depend on the technologies used in the devices makes new technologies dependent on new devices. This situation causes great cost and time loss for the user. In order to get rid of such problems, to some extent, the approach of using software in networks has been adopted. The Software Defined Network (SDN) paradigm has been developed in order to make the traditional networks a dynamic structure, to facilitate network management and to provide functionality to the network devices through software, to save users from device dependency. In this thesis, some precautions necessary for the security of the Dynamic Host Configuration Protocol (DHCP) servers, which automatically provide the necessary configurations for the internet access of the devices in computer networks, are mentioned. In this context, rogue DHCP attacks were studied. SDN approach was used to prevent the activities of a rogue DHCP server on the network. Thus, after detecting rogue DHCP servers on the network, measures to prevent IP distributions were taken. The studies were carried out in Mininet simulation environment.