Mitigation of DDoS attacks in Software Defined Networks at application level

Software-Defined Network's (SDN) core working depends on the centralized controller which implements the control plane. With the help of this controller, security threats like Distributed Denial of Service (DDoS) attacks can be identified easily. A DDoS attack is usually instigated on servers by sending a huge amount of unwanted traffic that exhausts its resources, denying their services to genuine users. Earlier research work has been carried out to mitigate DDoS attacks at the switch and the host level. Mitigation at switch level involves identifying the switch which sends a lot of unwanted traffic in the network and blocking it from the network. But this solution is not feasible as it will also block genuine hosts connected to that switch. Later mitigation at the host level was introduced wherein the compromised hosts were identified and blocked thereby allowing genuine hosts to send their traffic in the network. Though this solution is feasible, it will block the traffic from the genuine applications of the compromised host as well. In this paper, we propose a new way to identify and mitigate the DDoS attack at the application level so that only the application generating the DDoS traffic is blocked and other genuine applications are allowed to send traffic in the network normally.