JOURNAL OF INFORMATION, KNOWLEDGE AND RESEARCH IN COMPUTER ENGINEERING ISSN: 0975 – 6760| NOV 12 TO OCT 13 | VOLUME – 02, ISSUE – 02 Page 326 A MODIFIED HYBRID PROTOCOL(ZRP) USED FOR DETECTION AND REMOVAL OF BLACK HOLE NODE IN MANET 1 MR. RAJDIPSINH D. VAGHELA, 2 PROF. NISHANT J. GOSWAMI 1 M.E. [Computer Engineering] Student, Department Of Computer Engineering, Marwadi Education Foundation Group Of Institutes, Rajkot, Gujarat 2 Asst.Professor, Department Of Computer Engineering, Marwadi Education Foundation Group Of Institutes, Rajkot, Gujarat rajdipsinhvaghela90@gmail.com , nishant.j.goswami@gmail.com ABSTRACT: A Wireless ad-hoc network is a temporary network set up by wireless mobile Computers moving arbitrary in the places that have no network infrastructure. Since the nodes communicate with each other, they co-operate by forwarding data packets to other nodes in the network. Thus the nodes find a path to the destination node using routing protocols. However,due to security vulnerabilities of the routing protocols, wireless ad-hoc networks are unprotected to attacks of the malicious nodes. One of these attacks is the Black Hole Attack against network integrity absorbing all Datapackets in the network.In Black hole attack malicious node uses its routing protocol in order to advertise itself for having the shortest path to the destination node or to the packet it wants to intercept. This Paper Focus on to detect black hole node and remove it. The detection techniques which make use of proactive routing protocol have better packet delivery ratio and correct detection probability, but have higher overheads. The detection techniques which make use of reactive routing protocols have low overheads, but have high packet loss problem. Therefore, Using a hybrid detection technique which combines the advantages of both reactive and proactive routing Protocol to detect the black hole node. Keywords— Black hole, Zone routing protocol(ZRP),Packet Delivery Ratio, Throughput . I: INTRODUCTION Hybrid protocols exploit the strengths of both reactive and proactive protocols, and combine them together to get better results. The network is divided into zones, and use different protocols in two different zones i.e. one protocol is used within zone, and the other protocol is used between them. Zone Routing Protocol (ZRP) is the example of Hybrid Routing Protocol. ZRP uses proactive mechanism for route establishment within the nodes neighborhood, and for communication amongst the neighborhood it takes the advantage of reactive protocols. These local neighborhoods are known as zones, and the protocol is named for the same reason as zone routing protocol. Each zone can have different size and each node may be within multiple overlapping zones. The size of zone is given by radius of length P, where P is number of hops to the perimeter of the zone. Fig. 1.1, where the routing zone of S includes the nodes A–I, but not K. In the figure the radius is marked as a circle around the node. It should however be noted that the zone is defined in hops, not as a physical distance. The nodes of a zone are divided into peripheral nodes and interior nodes. Peripheral nodes are nodes whose minimum distance to the central node is exactly equal to the zone radius r. The nodes whose minimum distance is less than r are interior nodes[1]. Figure 1.1: Zone routing protocol (radius r = 2) [1] In Fig. 1.1, the nodes A–F are interior nodes; the nodes G–J are peripheral nodes and the node K is outside the routing one. Note that node H can be reached by two paths, one with length 2 and one with length 3 hops. The node is however within the zone, since the shortest path is less than or equal to the zone radius. ZRP refers to the locally proactive routing component as the IntrA-zone Routing Protocol (IARP). The globally reactive routing component is named IntEr-zone Routing Protocol