International Journal of Innovative Research in Engineering & Management (IJIREM) ISSN: 2350-0557, Volume-2, Issue-4, July 2015 1 Good Neighbour Node Detection Technique in Manets Using Enhanced QOS GNDA Mrs. Pallavi Patil , Mrs. Arpana Morey Department of Computer Engineering Pillai’s College of Engineering and Technology ABSTRACT As MANETS (Mobile Ad hoc Networks) is quickly spreading for the property of its capability in forming temporary network without the aid of any established infrastructure or centralized administration, security challenges has become a primary concern to provide secure communication. Security in Mobile Ad-Hoc Network is the most important aspect for the basic functionality of network. MOBILE Ad hoc Networks (MANETs) are wireless networks which are characterized by dynamic topologies and have no fixed infrastructure. As such detection of a good neighbor node is a necessity. In the routing protocol called Quality of Service Good Neighborhood Node Detection Algorithms (QOS-GNDA) author find the good node but if malicious node present in network and if it makes entry in routing path then it causes security threat to sensitive data so we find the new Enhanced Quality of service Good Neighbor Node detection technique .we use Enhanced Highly Secure Approach against Attacks on MANETs (EHSAM) to overcome the data tempering problem. Keywords: MANETs, Adhoc routing, AODV, Signal strength, Flow capacity, Relative position, malicious node. 1 .INTRODUCTION There are several competent routing protocols available in mobile ad hoc network. Some protocol used table driven approach where some protocol used reactive approach. Selection of appropriate protocol for routing is essential factor for efficient and effective communication of data. While selecting the protocol various aspects need to count such as low network overhead, high throughput and high packet delivery ratio and delay in packet forwarding. In today’s era, security is essential for any system. MANETs should have secure way of communication & data transmission. The system should defend all kind of active & passive attacks, internal & external attacks. Various attacks such as black hole attack, grey hole attack, tunneling attack, flooding attack, selfish node misbehaving, spoofing, eavesdropping, Sybil attack, rushing attack, Denial of Service attack (DoS), impersonation attack, routing table overflow attack cause threat to MANET.A MANET is open to all these attacks due to communication among the nodes is on trust based, no central point for managing the network, limited resources such as battery and bandwidth, continuous change in topology & no authorization for new nodes before joining to network. Various approaches are used to overcome or to avoid network level attacks in different protocols. Mainly various encryption methods such as RSA, MAC, hash code etc. used to provide authentication & integrity of message. Some methods use digital certificates & public key infrastructure to achieve security goals in ad- hoc network. Watchdog & path rater used to avoid packet dropping attack & selection of path with high rating. By use of various methods & techniques to achieve security might increase overhead over the network. Each node has to do additional computations to achieve high security, which may increase overhead on node. The main aim of any approach should be provide effective and secure way of communication with minimum overhead, less computation. Various approaches are attack specific. That makes system vulnerable for colluding attack. To avoid such attacks various approaches needs to be used in combination This paper is organized as follows. Section 2 describes the impact of malicious neighbor nodes. In section 3, some of the good and malicious neighbor detection methods are reviewed. Section 4 presents proposed methodology for enhanced good neighbor node detection based on EHSAM using QOS-GNDA. Section 5 depicts consultation. 2. IMPACT OF MALICIOUS NODES The nodes in MANET have limited battery power and bandwidth, and each node needs the help of others to get its packets forwarded. The different protocols in MANETs assume that all the nodes are cooperative and whenever a node receives a request to relay traffic, it always does so truthfully. However the experience has shown that as the time passes there is a tendency in the nodes in an ad hoc network to become selfish. The selfish nodes are not malicious but are reluctant to spend their resources such as CPU time, memory and battery power for others. The problem is especially critical when with the passage of time the nodes have little residual power and want to conserve it for their own purpose. Thus in MANET environment there is a strong motivation for a node to become selfish. The working of Adhoc network is based on packet forwarding using neighbor nodes, the source or the sender node must rely on intermediate nodes. The dynamic nature of network topology in Adhoc network leads the problem for nodes like, limited bandwidth, hidden terminals, transmission errors, and battery constraints, selfish nodes. The nodes affected by this gives poor performance ultimately the network throughput and network protocol affected and the performance of the network is decreases. 3. EXISTEM SYSTEMS In MANET there is lack of central administration system which monitors the nodes and find out which node is misbehaving. Here each node forwarding the packet to next node on simply trusting it and increase the threat to system. Attacker can easily make any node to compromises on security goals by launching internal or external attack.