KarmaNet: SDN Solution to DNS-Based Denial-of-Service

Networks are fundamentally designed to efficiently share network resources among end-users. The Internet has facilitated a global communication and computational environment by interconnecting billions of computers. People depend on the Internet to share professional, personal, confidential, and valuable information with other network users. Because of this high dependency of users, attackers often exploit its weaknesses to paralyze crucial and important segments of the Internet. Domain Name System (DNS) is one such segment whose proper functioning is highly crucial for the Internet to function properly. Attackers often exploit vulnerabilities of the Internet and DNS to launch large scale Distributed Denial of Service (DDoS) attacks and disrupt network services. Such DNS based DDoS attacks generally use IP spoofing to bombard target network/host so as to paralyze them with attack packets. In this paper we present a novel DDoS attack prevention mechanism by utilizing the flexibility and programmability aspects of Software Defined Networks (SDN). The principal philosophy used behind it is to route DNS response packets along the same path which was used by corresponding DNS request packet. Such routing is independent of the destination IP address present in the packet. This way, the malicious host responsible for launching DDoS attack will self-destruct itself. The results of the simulation showed that KarmaNet reduced the network delay by 41% when the network was experiencing a DDoS attack. Also, as any security mechanism comes at a cost, simulations of proposed mechanism shows that it also introduced additional delay of 8%–9% in getting DNS responses as compared to current DNS structure.