International Journal of Engineering, Management & Sciences (IJEMS) ISSN-2348 –3733, Volume-4, Issue-1, January 2017 5 www.alliedjournals.com Abstract— As MANET (Mobile Ad-hoc Network) applications are deployed, security emerges as a central requirement. we introduce the wormhole attack, a severe attack in ad hoc networks that is particularly challenging to shield against. The wormhole attack is possible even if the intruder has not harm any hosts, and even if all communication provides authenticity and confidentiality. In the wormhole attack, an intruder records packets (bits) at one location in the network, tunnels them (possibly selectively) to another location, and retransmits them there into the network. The wormhole attack can form a serious threat in MANET, especially against many Mobile Ad-hoc Network routing protocols and location based security systems. For example, most existing MANET routing protocols, without some mechanism to defend against the wormhole attack, would not be able to find routes longer than one or two hops, severely interrupt communication. Here is a general mechanism, called packet watchdog, for detecting and protecting against wormhole attacks, and a specific protocol that implements watchdog. In this performance of Mobile Ad-hoc Networks (MANET) under wormhole attack is analyzed. Multiple QoS parameters have been considered here such as throughput, delay, packet delivery ratio, node energy and node density. The NS3 network simulator has been used and the reference point group mobility model is considered to study the effect of node density and the initial energy on the throughput. Index Terms—MANET, Reactive Protocol, Proactive Protocol, Hybrid Protocol, NS3. I. INTRODUCTION One of the most challenging goals in mobile ad hoc network is the design of routing protocols. The role of routing protocol is to find the shortest path between the source and the destination of a flow [1]. Routing protocols may generally be categorized as three types 1. Proactive Protocols Himanshu Gautam, Department of Computer Science and Engineering, Rajasthan Institute of Engineering and Technology, Jaipur, India, Amit Kumar Bairwa, Department of Computer Science and Engineering, SCIT, Manipal University, Jaipur, India Dr. Sandeep Joshi, Department of Computer Science and Engineering, SCIT, Manipal University, Jaipur, India 2. Reactive Protocols 3. Hybrid Protocols Proactive protocols are also referred to as table-driven while reactive protocols are referred to as on-demand. This protocols attempt to maintain consistent, up-to-date routing information from each node to every other node in the network. While on the other hand, reactive protocols initiate route discovery only in the presence of data for transmission at the source. TABLE 1 CLASSIFICATION OF MANET ROUTING PROTOCOLS MANAET Routing Protocol Reactive Protocol ABR ACOR AODV DSR Proactive Protocol CGSR DSDV OLSR WRF Hybrid Protocol ARPAM OORP TORA ZRF II. WORMHOLE AND IT’S VARIANTS This content is focuses on the wormhole attack, where two colluding nodes that are far apart are connected by a tunnel giving an illusion that they are neighbors. Each of these nodes gain route request and topology control messages from the network and send it to other colluding node via tunnel which will then replay it into the network from there. By using this additional drift, these nodes are able to advertise that they have the shortest path through them. Once this link is established, the attackers may choose each other as multipoint relays (MPRs), which then lead to an transaction of some topology control (TC) messages and data packets through the wormhole tunnel. Since these MPRs forward flawed topology information, it results in spreading of incorrect topology data throughout the network [8]. On Performance Evaluation of MANET in AODV Routing Protocol Under Wormhole Attack Using NS3 Himanshu Gautam, Amit Kumar Bairwa, Dr. Sandeep Joshi