Special Issue of International Journal of Computer Applications (0975 – 8887) on Wireless Communication and Mobile Networks, No.9. Jan.2012, ww.ijcaonline.org 42 Simulation Study of Black Hole and Jellyfish attack on MANET Using NS3 Nidhi Purohit Information Technology Dept.,L.D. College Of Engineering,Ahmedabad, India Richa Sinha Information Technology Dept.,L.D. College Of Engineering,Ahmedabad, India Hiteishi Diwanji Information Technology Dept.,L.D. College Of Engineering,Ahmedabad, India ABSTRACT Wireless networks are gaining popularity to its peak today, as the user’s wants wireless connectivity irrespective of their geographic position. There is an increasing threat of attacks on the Mobile Ad-hoc Networks (MANET). The attacks studied in this paper are against the routing protocols in Mobile ad hoc network. We have used AODV for simulating this attacks using NS3. Black hole attack is one of the security threat in which the traffic is redirected to such a node that drops all the packets or the node actually does not exist in the network. Black holes refer to places in the network where incoming traffic is silently discarded or dropped. Jellyfish (JF) attack is a type of selective black hole attack. When JF node gets hold of forwarding packet it starts delaying/dropping data packets for certain amount of time before forwarding normally. Since packet loss is common in mobile wireless networks, the attacker can exploit this fact by hiding its malicious intents using compliant packet losses that appear to be caused by environmental reasons General Terms Table, Graphs and results Keywords AODV protocol, Black hole & Jellyfish attack, Mobile ad hoc networks (MANETs), Network Simulator-3 1. INTRODUCTION The mobile ad-hoc network (MANET) is a self-configuring infrastructure-less network of mobile devices connected by wireless links [1]. Each device in a MANET is free to move independently in any direction, and will therefore change its links to other devices frequently. Each must forward traffic unrelated to its own use, and therefore be a router. The primary challenge in building a MANET is equipping each device to continuously maintain the information required to properly route traffic. Such networks may operate by themselves or may be connected to the larger Internet. MANETs are a kind of wireless ad-hoc networks that usually has a routable networking environment on top of a Link Layer ad hoc network. The strength of the connection can change rapidly in time or even disappear completely. Nodes can appear, disappear and reappear as the time goes on and all the time the network connections should work between the nodes that are part of it. As one can easily imagine, the situation in ad hoc networks with respect to ensuring connectivity and robustness is much more demanding than in the wired case. Such types of dynamic networks are more vulnerable to attack than compared to wired network. This is because of the following reasons: Open Medium Dynamically Changing Network Topology Cooperative Algorithms Lack of Centralized Monitoring Lack of Clear Line of Defence Therefore, MANET inherits security threats that are faced in wired as well as wireless networks and also introduces security attacks unique to itself [3]. Simulation and study of such attack has become necessary in order to provide defend mechanism between these types of attacks.The remainder of this paper is organized as follows: In section II, we have introduced some background study and related work that gave the motivation of this paper. In section III, we give overview of AODV. In section IV, we discuss both Jellyfish and Black hole attack. In section V, we present simulated results based our study and set up on NS3. Finally, section VI concludes the paper with some future research enhancement. 2. BACKGROUND AND RELATED WORK In ad hoc networks, routing has become the big challenge due to presence of Wireless network [4]. Dynamic routing protocols are of two types. First is proactive routing likes DSDV [5] which are table driven and second is reactive protocol like AODV [6] and DSR [7] which are on demand routing. MANETs are dynamic in nature and follow up on demand nature so AODV and DSR can be used because network will force the host to rely on each for maintaining stability. In these protocols forma every node (or Radio terminal) communicates with its partner so as to perform peer to peer communication. If the required node is not a neighbour to the initiated call node, then the other intermediate terminal are used to perform the communication link. This is called multi-hop peer to peer communication [2]. The collaboration between these nodes is very important in the ad hoc networks. Now, in this type of scenario if some misbehaving nodes[8] first agrees to send the packet and refuse to do so because of node’s overhead , connection broken, node selfishness and maliciousness, then successful transferring of data will be compromised. Node overhead is done due to increase in CPU cycle, there is no buffer space availability and connection can be broken because of dynamicity of the network. In such case network suffers the general issues for packet lost. But when a node is getting selfish for saving its own resource [9] or becoming malicious [10] by indulging DoS attack by dropping packets then in such case network suffers a genuine packet loss. In our analysis we will provide with the simulation of DoS attacks [11] [16] like Black hole and Jellyfish attacks. The