PREVENTION OF DOS AND BLACK HOLE ATTACK IN AODV

1. A DISSERATION On PREVENTION OF DOS AND BLACK HOLE ATTACK IN AODV For the award of the degree of Master of Technology (Computer Science and Engineering) Session 2014 – 2016 Submitted by Supervised By Mrs. Harsha Chawla Sachin Gupta S14MCSE11 Assistant Professor Department of CSE, NGFCET, Palwal Department of CSE, NGFCET, Palwal MAHARSHI DAYANAND UNIVERSITY Fore More info Https://www.ThesisScientist.com

2. CHAPTER 1 INTRODUCTION 1.1OVERVIEW The cellular networks or mobile networks are a communication networks where the last link is wireless. The networks to be distributed over land areas called cells, each served by at least one fixed-location transceiver, known as a cell site or base station. The wireless cellular systems are being used since 1980s. We have seen their evolutions such as first, second and third generation's of cellular wireless systems. These systems work with the support of a centralized supporting structure such as the access point. In ad-hoc network wireless users can be connected with the wireless systems with help of these access points, when they want to roam from one place to the other. The adaptability of the wireless systems is limited by the presence of a fixed supporting coordinates. It’s mean that the technology can’t work efficiently in the places where is no permanent infrastructure. Such type the fast network deployment is not possible with the existing infrastructure of present wireless systems. Recent advancements such as Bluetooth’s introduced a fresh type of a wireless system that is frequently known mobile ad-hoc networks. The mobile ad-hoc networks control does not depends upon the permanent preexisting infrastructure. The mobile ad-hoc networks offers quick and horizontal networks deployment in certain conditions where it is not possible otherwise. The Ad-hoc word is a Latin word meaning of that is "for this or for this only." Mobile ad-hoc networks are an Fore More info Https://www.ThesisScientist.com

3. autonomous system of the mobile nodes that are connected by wireless links; each node operates as an end system and a router for all other nodes in the network. The wireless networks are a growing new technology that will allow users to access services and information electronically in respective of their geographic position. Wireless networks can be classified into two types such as infrastructure networks and infrastructure less networks. Infrastructure network consists of a network with fixed and wired gateways. A mobile node or host interacts with a bridge in the network known as base station within its communication radius. The mobile nodes are able to move geographically while these are communicating with others. When mobile node goes out of the range of one base station, it connects with other new base station and starts communication. This is known as handoff and in this approach the base stations are fixed. The Mobile Ad-Hoc Network is a group of wireless mobile nodes in that nodes to be collaborated by forwarding packets to other to allow them to communicate outside range of direct wireless transmission. The Ad-Hoc network does not need any types of centralized administration or fixed network infrastructure such as base stations or access points, and can be quickly and inexpensively set up as needed. In other words we can say MANET is an autonomous group of mobile users that communicate over the reasonably slow wireless links. The network topology may vary rapidly and unpredictably over time, because the nodes are mobile. The MANET is decentralized, where all the networks activity, including discovering. The topologies and delivery of the messages must be executed by the nodes themselves. Hence routing functionality will have to be incorporated into the mobile nodes. Fore More info Https://www.ThesisScientist.com

4. AB c Figure 1.1 Example of a simple ad-hoc network with three participating nodes The Mobile Ad-Hoc network is a collection of independent mobile nodes that can communicate to each other via radio waves. The mobile nodes are able to directly communicate to those nodes that are within the range of radio range of each other, and node beyond the communication range need the help of intermediate nodes to route their packets. These networks are fully distributed, and can work at any place without the help of any infrastructure. This property makes these networks highly robust. In Figure 1.1 nodes A and C must discover the route through B in order to communicate. The circles indicate the nominal range of each nodes radio transceiver. Node-A and Node-C are not in the direct transmission range of each other, since Node-A’s circle does not cover the Node-C .So if A want to send a data to C it is obvious to involve B to forward the data from A to C. Here B acts as an intermediate node. Without node B A cannot send the data to C. MANET is a kind of wireless ad-hoc network and it is a self-configuring network of mobile routers (and associated hosts) connected by wireless links the union of which forms an arbitrary topologies. The participating nodes acts as a router are free to move randomly and manage themselves arbitrarily. Thus the wireless network's topology may Fore More info Https://www.ThesisScientist.com

5. change rapidly and unpredictably such type networks may operate in standalone fashion, or may be connected to the larger internet. Mobile Ad-hoc Networks is a collection of group of wireless mobile node, i.e wireless devices. The wireless nodes are connecting dynamically and sharing the information. Basically there are two types of mobile ad-hoc networks: Infrastructure based and networks with fixed and wired gateways. The bridges for wireless networks are known as base station [1].The personal computer make wireless node using the wireless LAN card, the PDA (Personal Digital Assistants) or Smartphone, the laptop or wireless devices. Fig: 1.1 Mobile Ad-hoc Networks Fig.1.1 is defining the mobile ad-hoc network and how to communicate one wireless device to another wireless device. A wireless node can be tackle of any employs. The air as the transmission medium. As shown, wireless node may be physically connected to a Laptop, a Mobile, or PDA, to enable wireless communication between them. Fore More info Https://www.ThesisScientist.com

6. 1.2Characteristics of an Ideal Routing Protocol for Ad Hoc Wireless Network Due to the issue in an Ad-Hoc wireless network environment discussed so for the wired network routing protocols cannot be used in Ad-Hoc wireless networks. Hence Ad-Hoc wireless networks always require specialized routing protocols that address all those challenges that are described above. The routing protocols for the Ad-Hoc wireless network should contain following characteristics:  It must be fully distributed as like centralized routing involves the high control overhead and hence it cannot scalable. The distributed routing mechanism is more fault-tolerant than centralized routing, which involves the risk of single point of failure.  It must be adaptive to the frequent topology changes caused by the mobility of the nodes.  The route computation and maintenance must be involved a minimum number of nodes. Each node in the network must have quick access to the route, that is, minimum time connection set up time is desired.  It must be localized, as the global state maintenance involves a huge state of the propagation control overhead.  It must be loop- free and free stale routes. Fore More info Https://www.ThesisScientist.com

7.  The collisions of packets must be kept to a minimum by limiting the number of broadcasts made by each node. All transmissions should be reliable to the reduce message loss and prevent the occurrence of the stale routes.  It must be covered to the optimal routes once the network topology becomes stable. The convergence must be quick.  It must optimally use the resources such as bandwidth, computing power, memory, and battery power.  Every node on the network should try to store the information regarding stable local topology only.  It should be able to provide a certain level of quality of services (QoS) as demanded by applications, and should also offer support for time-sensitive traffic. 1.3 Characteristics of MANET The Mobile Ad-Hoc Network nodes are furnished with wireless transmitters and receivers using antennas, that may be highly directional (point-to-point), omnidirectional (broadcast), probably steerable, and combination thereof. At the given point in time, depends on positions of nodes, their transmitter and receiver coverage patterns, the communication power levels and co-channel interference levels, the wireless connectivity in the form of a random Ad-Hoc network exists among the nodes. This Fore More info Https://www.ThesisScientist.com

8. Ad-Hoc topology may modify with the times such as when nodes move or adjust their transmission and reception parameters in the range. The characteristics of these networks are summarized as follows:  Dynamic topologies: In this nodes are free to move randomly, thus the network topology that is typically multi-hop, may be changed randomly and rapidly at the unpredictable time, and may consist of both unidirectional and bidirectional links.  Energy-constrained operation: Some or all of the nodes in a Mobile Ad-Hoc Network may rely on power bank like a battery or other exhaustible means for their energy. For all of these nodes the most important system design criteria is energy conservation for optimization.  Bandwidth-constrained & variable capacity links: The wireless links will be having a significantly lower capacity than their hardwired counterparts. Furthermore, afteraccounting of the effects of multiple accesses, fading, noise, and interference conditions, the realized throughputs of the wireless communications are often more less than a radio's maximum transmission rate.  Limited physical security: The mobile wireless networks are normally much prone to the physical securities threats than fixed-cable nets. The increased possibilities of the eavesdropping, spoofing, and denial-of-service attacks need to be carefully considered. Existing link securities techniques are often applied Fore More info Https://www.ThesisScientist.com

9. within the wireless networks to reduce securities threats. As a benefit, the decentralized nature of the networks control in MANETs always provides additional robustness against the single points of failure of more centralized approaches.  Energy constrained function: Because battery used in every mobile node have certain restricted power supply, limited processing power, which in turn limits services and applications supported by each and every node. It becomes a big issue in MANET because, as each node is act as a router and an end system at the same time, to forward packets from other node addition energy is required.  Independent and infrastructure-less: MANET does not depend on traditional infrastructure or centralized administration. Every one node operates in spread peer-to-peer mode, behaves as an independent router and generates an independent data. Network managing has to be scattered across different nodes, which brings added difficulty in fault finding and managing.  Frequently/Dynamically changing network topologies: In MANET’s, nodes can easily move randomly, the network topology, which is normally multi-hop, can change commonly and unpredictably, resulting in route changes, possibly packet losses and frequent network partitions [4]. Fore More info Https://www.ThesisScientist.com

10.  Multi-hop routing: No any predefine router is available; every node behaves as a router and forwards each other’s packets information to enable the sharing information between nodes and mobile hosts.  Variation within a link and node capability of node: Each node ready with one or more radio interfaces that have varying capabilities of transmission/receiving and manage across the different frequency bands [14].  Communication via wireless means.  Nodes can perform the rolls of both hosts and routers.  Frequent routing updates 1.4 The advantages of Mobile ad-hoc networks are Deployment cost is low: Ad hoc networks can be deploy on the fly, for this reason no more costly infrastructure such as copper wires or data cables is not required.  Fast and easy deployment: Ad hoc networks are very well-situated and simple to deploy, since there are no cables involved. So the deployment time can be reduced. Fore More info Https://www.ThesisScientist.com

11.  Dynamic Configuration: Ad hoc network configuration changes dynamically over the time in MANET’s. While comparing to configurability of LANs, it is very easy to change the networks topology of a wireless mobile ad-hoc network. MANET has different feasible application. Some of them include emergency search- rescue operations, communication in the battlefield during moving vehicles and soldiers. Conferences and meeting. 1.1.3Application of MANET Sensor networks: •Inside the home Smart sensor and actuators embedded in consumers electronic • Body area networks (BAN) •Data tracking of animal movements, chemical/biological detection and environmental conditions. Tactical networks: • Military communication • Military operations • In the battlefields Fore More info Https://www.ThesisScientist.com

12. Emergency services: • Rescue operations and Search in the mountain and the desert. • Replacement of fixed infrastructure. i.e. in case of environmental calamities. • Policing. • Fire Alarm using sensor networks • Supporting doctors and nurses in hospitals. Coverage extension: • Extending cellular network access • Link up with the intranets, Internet, and so on. Education: • Campus settings and Universities. • Classrooms. • Ad hoc Network created for a meetings or lectures. Home and enterprise: • Used in the wireless networking in office or home. Fore More info Https://www.ThesisScientist.com

13. • Conferences, meeting rooms. Context aware services: • Follow-on services: mobile workspace, call-forwarding, • Information services: time dependent services, location specific services. Commercial and civilian environments: • E-commerce: electronic payments • Business: mobile offices and dynamic database access • Shopping malls, trade fairs, sports stadiums and so on. • Networks of visitors inside the airports [5]. 1.4Disadvantages of MANET Some of the disadvantages of MANETs are as follows;  Limited resources and physical security  Intrinsic mutual trust vulnerable to attacks  Lack of authorization facilities  Volatile network topology makes it hard to detect malicious nodes Fore More info Https://www.ThesisScientist.com

14.  Security protocols for wired networks cannot work for ad hoc networks. 1.1.4Challenges of MANET Dynamic topology/Networks: Nodes are mobile and connected dynamically in a random manner. Links of the network vary timely and are based on the closeness of one node to another. Independent Network: No centralized administration node is available to handle the operation of the different mobile nodes. Device discovery: Identifying relevant mobility in nodes and informing about their existence need movable updates, route selection to facilitate automatically Bandwidth optimization: The wired links have higher capacity then wireless links Resource limitations: Mobile node depends on battery power, power and storage capacity. Scalability: Scalability could be defined as whether network is able to provide an acceptable level of services even in a presence of the extensive number of nodes. Ad-hoc addressing: It belongs to addressing scheme which is to be implemented. Fore More info Https://www.ThesisScientist.com

15. Network configuration: The dynamic connection and disconnection of the variable links. Of MANE infrastructure is due to dynamic nature. Topology maintenance: Updating information of dynamic links among the nodes in MANETs is a great challenge [6]. 1.2 Motivation Mobile Ad-Hoc Networks are most usefully in current environments. It’s required high performance, networks load and Throughput. In Mobile Ad-hoc Networks Routing is the hot topic for research. Basically two types routing protocols are work in the mobile Ad- hoc Networks: 1) Proactive and 2) Reactive. Researchers have projected different routing algorithm. Important work has been done on routing in ad hoc networks, some of the important works so far were the destination-sequence distance vector (DSDV) protocol, the temporally ordered routing protocol (TORA), dynamic source routing protocol (DSR) and ad hoc on demand routing protocol (AODV). These algorithms use Open Shortest Path First (OSPF) for find optimum route source to destination. Malicious node is the main responsible for disturb the correct operation and reduce the performance and throughput. Only malicious node is responsible for all possible attack in mobile ad-hoc networks. Fore More info Https://www.ThesisScientist.com

16. 1.3 Problem statement In Ad hoc network where node work as a mobile and changing their position in the network continuously so network is affected from malicious behavior node. Performance of AODV is affected by the malicious behavior node because it is main security threat in the MANET network. This type of problem is arising due to routing performance in malicious .behavior node environment. Throughput and End-to End delayed depend on number of nodes as the number of nodes increase, Throughput will decrease and End-to End delayed increases. We are lagging in securing the network of AODV due to this malicious behavior environment with less delay. 1.4 Goal The main objective of work is to check performance of Network in malicious behavior of node environment and provide the prevention to the attack. Analysis of prevention scenarios, Throughput and end-to-end Delay for Denial of Service (DoS) and Black Hole attacks and. Fore More info Https://www.ThesisScientist.com

17. The main focus of work for securing the network in malicious behavior environment with less delay. Which improve the performance of MANET and improve packet delivery rate. 1.5 Routing protocols in MANET In Mobile ad hoc network Routing is primarily and most important concept for communication in the network. The aim of routing is to find out and select the best route between communicating node, when a communication take place between nodes in the network intermediate node play a important role because when source node send route request to destination node and destination node give reply of the route request to source node, In this intermediate node take a part in communication between source to destination, then create a route reply and sends the route reply to the source node through intermediate node. 1.5.1Characteristics of Routing Protocol It must be fully distributed in dynamic environment. It must be adaptive to frequent topology changes caused by the mobile nodes. It has an intelligent route discovery process and uses a loop-free routing. It produces reliable end-to-end transmission using limited bandwidth, memory, battery and computing power. It maintains the particular level of quality of service. Fore More info Https://www.ThesisScientist.com

18. 1.6 Classifications of routing protocols There are three types of routing protocols in Mobile ad-hoc networks. 1.Table Driven Routing Protocols. 2.On Demand Routing Protocols. 3.Hybrid Routing Protocol The DSDV (Destination Sequenced Distance Vector Routing protocols), WRP (wireless Routing protocol), OLSR (Optimized Link State Routing Protocol) is the Table driven Routing protocols and AODV (Ad-hoc On-Demand Distance vector routing protocol), DSR (Dynamic Source Routing protocol) are the On-Demand Routing Protocols. Routing Protocols in MANET Table Driven Routing Protocols On Demand Routing Protocols Hybrid Routing Protocols DSDV WRP OLSR AODV DSR Fig. 1.2 Classification of Routing Protocol in MANET Fore More info Https://www.ThesisScientist.com

19. 1.6.1Table Driven Routing Protocols: It is also called Proactive Routing Protocols. The Proactive means it works or maintains the routing information before the source node wants to send packet or information to the destination. The Table Driven Routing protocols maintain the updated path from each to every node available in the networks. In these protocols every node needs to maintain the routing table for storing the routing information. When topology of network gets any changes, then routing table also get updated and stores the fresh or up-to date information. 1.6.1.1 Destination Sequenced Distance Vector Routing Protocols (DSDV): The Destination sequence distance vector routing protocols (DSDV) is the Table Driven Routing Protocols. It is based on the Bellman-ford Routing Algorithm. The bellman algorithm is used for finding the optimum path or route in the network. The Fig1.3 (a) is DSDV routes establish for mobile networks. In this network nodes are connected to each other. Table 1.1 (b) here is defining the routing table for Node 1. Node 1, routing table is storing the information of every node connected to the network. The routing table consists of information like Destination from Node 1, Next hop, Distance between Node 1 to other nodes and randomly generated Destination Sequence number. Fore More info Https://www.ThesisScientist.com

20. 4 5 3 8 2 7 6 1 Fig 1.3 (a) DSDV Route Establish: Networks Destination Next Hope Distance Destsequence 2 2 1 22 3 2 2 37 4 2 2 41 5 2 4 50 6 2 3 99 7 2 4 121 8 2 5 109 Table 1.1 (b) DSDV Route Establish: Node 1 Routing In this protocol every node maintains a routing table that lists all current destinations. The number of hops required reaching source node to destination node and sequence Fore More info Https://www.ThesisScientist.com

21. number is assigned by the destination node. Sequence number is used to decide old route from new one and also to ignore the configuration loops. The node has frequently broadcast their routing table to their immediate neighbors. Every node also broadcast its routing table, if any change has occurred in its table from the last update. In Fig 1.4 (a) and Table 1.2 (b) Node 7 is disconnected from Node 6 and established connection with Node 8. So the routing table of Node 7 updated. Node 6 notices the link-break and sends the updates with new route information. Table Driven routing table updates are of two types: Full dumps and Incremental updates. If the routing table updating is full dump, then the whole routing table to be sends to the neighbor’s node. It update incrementally, only position changed entries sent from the routing table since the final update and fit in a packet. 4 5 3 8 2 7 6 1 7 Fig 1.4 (a) DSDV Route Maintenance Fore More info Https://www.ThesisScientist.com

22. Destination Next Hope Distance Destsequence 2 2 1 22 3 2 2 37 4 2 2 41 5 2 4 50 6 2 3 99 7 2 4 121 8 2 5 109 Table 1.2 (b) DSDV Route Maintenance When MANET network is stable, then incremental updates are sent to avoid over traffic. If space in the update increments, then those entries whose sequence number has been changed may be included. If two routes have the same sequence number then based on the previous information or record, the shortest route will choose by the node and also guess the settle time of routes. DSDV protocol reduces the Count to infinity problem and provides loop free paths. Fore More info Https://www.ThesisScientist.com

23. 1.6.1.2 Wireless Routing Protocol (WRP) Wireless routing protocol is distance based distributed Bellman-Ford algorithms. and is similar to DSDV. The WRP protocols can hold the routing information about all communicating nodes in the network. WRP protocol maintains the precise and up-to- date information about the network. In each node four routing tables were maintained namely Message Transmission List (MST) are maintained. Distance Table (DT), Link Cost Table (LCT) and Routing Table (RT). The Distance Table (DT) consists of the destination node of distance and predecessor node is maintained by neighboring nodes of that destination. All the up-to-date information of destination is maintained by the Routing Table (RT). It also records the hop number, shortest distance of path, from source to destination, predecessor & successor node and flag. The flag indicates the status of the path. These are simple path or a loop or the destination node not marked. Therefore this protocol avoids the problem of counting-to-infinity. The Link Cost Table contains cost, hop number and periodic updates. The broken link cost is denoted by (∞). The Message Transmission List (MSL) contains retransmission of counter, the sequence Number, list of updates for updating of the messages. Update each message maintains the list of updates. Each and every transmission, the counter value is decreased. The entry of each node is stored in Routing Table (RT). Each node propagates the update messages within the network. If a node is not sending the update messages, then it must send any other node’s message within the time for Fore More info Https://www.ThesisScientist.com

24. continuing the connectivity. Similarly, if each node receives a message from new node, then the new node entry must stored in the route table for avoiding the count-to-infinity problem. 1.6.1.3 Optimized Link State Routing Protocol (OLSR) Optimized Link State Routing Protocol is a proactive or table-driven routing protocol. It is also a pure link state routing protocol. Optimized Link State Routing (OSLR) hold request message i.e. hello message and Topology Control (TC) Messages to search the link messages entire the network. The protocol manages neighbour sensing, MPR selectors (Multipoint Relay) and MPR information. Each node are using MPR selectors for selecting one-hop & two-hop neighbours and also for periodically broadcasting the messages over the network. The neighbour sensing hello messages contains list of the address of neighbours with bi-directional link or two- hop neighbours. The neighbour node is selected on the basis of MPR selectors. Each node selects its own set of Multi Point Relay. MPR information contains TC messages and topology table. The TC messages use the MPR selector table and sequence number to send their updates throughout the network. The TC messages and routing tables were maintained by the topology table. Each node maintains routing table. It consists of Destination address, Next-hop-address and Distance for all known destination in the network. Routing paths are calculated by the topology tables and recalculated after every updates in the network Fore More info Https://www.ThesisScientist.com

25. in the neighboring route. Every node broadcast periodic message in the network, and gets message using topology control message. Therefore, entry exist in topology table for the same destination with higher sequence number, then the TC message for same destination with low sequence number is discarded and also the new entry is recorded 1.6.2On-Demand Routing Protocols An on-Demand routing strategy creates and maintains path between source and destination only when required and does not maintain a permanent routing entry in routing of each destination. It includes two processes: Discovery of Route: When the source node, S wants to send a packet to the destination node, it first checks its routing table to find the route to the destination, if it is there, then the same route will use. Otherwise, it initiates process of route discovery process through a packet having the address of destination and the address of intermediate nodes to the destination. Route maintenance: Due to nature of node mobility or routing overhead, the nodes changes their topology and hence the route maintenance must do. Route maintenance is processed through the use of topology update messages (acknowledgement). There are two types’ reactive routing protocols. AODV (Ad-hoc On Demand Distance Vector Routing Protocols) DSR (Dynamic Source Routing Protocols) Fore More info Https://www.ThesisScientist.com

26. 1.6.2.1 AODV (Ad-hoc On Demand Distance Vector Routing Protocols) Ad-hoc On-Demand Distance Vector Routing Protocol is using a multi-hop technology based on distance vector routing protocol. The routes were created only when needed for communication between source and destination through intermediate mobile hosts. In AODV [3], Ad-hoc means node move or connected or disconnected with the networks any time, On Demand means when a source node, S wants to send data to the destination, D, Distance means find the distance between source to destination in terms of number of hope counts and Vector means list of information stored in the node’s information list. Every transmission using Source Address, Destination Address, Source ID, Destination ID, Source Sequence Number, Time to Live (TTL) Destination Sequence Number. These protocols use the Open Shortest Path First (OSPF) method/Algorithm. The AODV algorithm uses some approaches for path or route establishment [13]. Route Request (RREQ): In Route Request source node broadcast/transmit the route request message for specific destination neighbor’s node to pass the message to destination Route Reply (RREP): In Route Reply, destination uses the unicast route for reply message to source. The neighbor nodes make next hop entry for destination and forward the reply. If source receives multiple replies then it use the replies whose one with the shortest hop count route/path. Fore More info Https://www.ThesisScientist.com

27. SSN (Source Sequence Number) and DSN (Destination Sequence Number): When source node sends the broadcast packet with sequence number and destination sequence number, then it is defining the fresh path. Route Error (RERR): When a route error message is generated in the network then there is a network link break between sources and destination. The AODV routing protocols detects nodes if there is possible do the local repairing. When link break occurred in optimum path then the neighbouring node to sent previous request for sending the message to destination. RREQ 3 4 Source Destination 1 8 6 5 7 2 Fig 1.5 Route Request Message in AODV Fig 1.5 is a mobile wireless network. Node 1 (Source) to Node 8 (Destination Node) flood the route request packets with a source sequence within the network. Node 1 send route request to all neighbors and neighbors through Destination. Fore More info Https://www.ThesisScientist.com

28. RREP 3 4 1 8 6 5 Source Destination 7 2 Fig 1.6 Route Reply Message in AODV In Fig 1.6 Destination uses the unicast path for the route reply. Destination in the figure is replying the route request on symmetric link. Destination Sequence number is defining the freshness of the route/path. In network source node counts the number of hop to reach the destination and find the route with minimum number of hopes. Source node selects this route for data transfer. RERR 3 4 1 8 Source Destination 6 5 7 2 Fig 1.7 Route maintenance Fore More info Https://www.ThesisScientist.com

29. In AODV route maintenance happens when link break in the network, it broadcasts the route error (RERR) packet to its neighbors, which in reply propagates the RERR packet towards the node whose routes may be affected due to the disconnected link. Then, the affected source node can re-initiate a route discovery process if the route is still desired. Neighbor node informs all other neighbors in the network that this link does not exist, so don’t send any packet on that link. In Fig 1.7 there is a link break between Node 4 and Node 8.So node 4 informs Node 3 that there is a link break so choose another optimum path. 1.6.2.1.1 Advantages of AODV The AODV protocol does not require any such inner organizational method to handle any routing process. In AODV routes are established on the demand basis and that destination sequence numbers are applied for finding the latest route to the destination node. The connection setup delay is lower. The AODV protocols are loop free and avoid the count to infinity problem. 1.6.2.2 DSR (Dynamic Source Routing Protocols) Fore More info Https://www.ThesisScientist.com

30. DSR also a reactive routing protocols. A node maintains the route caches containing source routes that it is aware of. The node update entry in the route cache and it learn regarding fresh or latest route. This routing protocol has two main phases: Route Discovery Route Maintenance. When source node wants to send information or packet to the destination, it searches in the route cache to find out whether there is an existing route to destination, if it found that unexpired path to the destination exists in route cache, and then it uses this path/route to send the packet or information. But if node does not have any route then it starts the route discovery process using broadcasting/transmitting a route request packet. The route request packet has source address and also has unique identification number. Every middle node checks whether it knows the route to destination. If it does not know, then it stores address to the route record of the packet and pass the packet to its neighbors. A route reply message generated either the middle node or destination node with up to date information about the destination after receiving the route request packet. A route request packet reach at node already contains in the route record, the sequence of hops are taken from the source to this node. The route request packet propagates through the networks. Fore More info Https://www.ThesisScientist.com

31. Destination ID Network Link 15 14 Route Request 13 Route Reply 12 11 Path1: 1-2-3-7-9-13-15 Path2:1-5-4-12-15 Path3:1-6-10-11-14-15 9 8 10 4 7 5 3 6 2 1 Source ID Fig 1.8 Route Establishment The route record is produced below as shown in Fig 1.8 if route reply is generated by the destination node, after this it places a route record from the route request packet into the route reply packet. If middle node generates route reply then it stores its cached route and sends to destination with route record of route request packet and adds that into the route reply packet. Fore More info Https://www.ThesisScientist.com

32. The route reply packet individually sent by destination itself. The node responding to route reply packet sent by destination has a route to source. If it has route to the source in its route cache then it will use that route. The reverse of route record use, if symmetric links are supporting. If symmetric link are not supporting then the node can start route discovery to source and can attach the route reply to this new route request. Destination ID Network Link 15 14 Select Path 13 Route Error 12 11 Broken Link 9 8 10 4 7 5 3 6 2 1 Source ID Fig 1.9 Route maintenance The route reply packet individually sent by destination itself. The node responding to route reply packet sent by destination has a route to source. If it has route to the source Fore More info Https://www.ThesisScientist.com

33. in its route cache then it will use that route. The reverse of route record use, if symmetric links are supporting. If symmetric link are not supporting then the node can start route discovery to source and can attach the route reply to this new route request. The DSR routing protocols use two type of packets for route maintenance: Route Error and Acknowledgements. When a node encounter a deadly broadcast problem at data link layer then it generate route error packet. When nodes receive the route error packet, it will remove the hop from its route cache. All routes that contain the hop in error are reduced at that position. Acknowledgement packets are used to verify the proper operation of the route link. Also include the passive acknowledgment in which the next hop passing the packet next to the route. 1.6.3Hybrid Routing Protocols The Hybrid routing protocol is combination of the both such as reactive and proactive routing protocols. It was proposed to minimize the control overhead of Proactive Routing Protocols and also to decrease the latency caused by route discovery within reactive routing protocols example of this is ZRP. ZRP was planned to minimize the control overhead of the proactive routing protocols and discovery in the reactive routing protocols and also decrease latency caused by the route. The ZRP consists of several numbers of components, and these together Fore More info Https://www.ThesisScientist.com

34. components give the benefits of ZRP. Each components work independently to provide the efficient result. Components of ZRP are:  IARP ( Intrazone Routing Protocol )  IERP ( Interzone Routing Protocol)  BRP (Boardercast Resolution protocol ) The IARP is the first component of ZRP. The IARP is used for the communication with the interior node inside a zone. If a network topology change, node may get change rapidly. it allow for only local route. IERP is a global reactive component of ZRP. It uses the reactive approach to communicate with nodes outside the zone. It changes the way a route discovery is handled. The route queries issued by IERP is when request for the route issue. BRP is used to direct the route request initiated by a global reactive IERP. It is used to maximize efficiency and increase the disused queries. 1.7 Organization of the Thesis Literature Survey is discussed in the chapter 2, this section is covered with various security issues, Taxonomy of AODV and Literature review of AODV. In chapter 3 various attacks in AODV and Problem statement are discussed such as Dos and Blackhole attack, malicious node and problem statement due to Denial of service attack and Black hole attack in the Network Layer. Fore More info Https://www.ThesisScientist.com

35. The chapter 4, in this proposed work of my research works is discussed. Explained the actually flow of research and explain about the research scheme. The chapter 5 and 6 consists of the experimental results and conclusion here defines the simulation model NS-2 for implementation and specification of parameters and discussed about the initials developed networks and after add malicious node for build up the Denial of Service and Black Hole attacks. Provide the results both environments in terms of End-to-End delay and Throughput. And Conclusion and future work of thesis. Fore More info Https://www.ThesisScientist.com

36. Appendix I- Terminology I.1 General Terms Bandwidth: Total link capacity of a link to carry information Channel: In this physical medium is divided into logical channel allowing possibly shared uses of the medium. Channels are made by available subdividing the medium into distinct time slots, distinct spectral bands. Convergence: The process of approaching a state of the equilibrium in that all nodes in the networks are agree on a consistent state about the topology using in the network. Flooding: Flooding is a process of delivering data or control message to every node within the any data network. Host: Any node that is not a router. Interface: A node attachment to a link Link: A communication facility or a medium over which nodes can communicate at the link layer. Loop free: Once a path has been taken by a packet never transits the same intermediate node twice before arrival at the destination. Neighbor: The node within transmitter range of another node on the same channel. Fore More info Https://www.ThesisScientist.com

37. Next hop: A neighbor, which has been designed to forward packets along the way to a particular destination. Fore More info Https://www.ThesisScientist.com

38. CHAPTER 2 LITERATURE SURVEY 2.1 Routing Protocols Routing is the mechanism used to move data information from one place such as source node to another place such as destination node on the internetwork. At least one intermediate node of the internetwork will be encountered during the transfer of information. In the routing normally two activities to be involved in this concept such that first one is as determining optimal routing paths and second one is that transferring of the packets through the network. The transferring of data packets on the network through an internetwork is called as packet switching. Routing protocols use several metrics as a standard measurement for calculating a best path for routing the packets to its destination on the network that could be number of hops, which are used by the algorithm known as routing algorithm to determine the optimal path for the packet to its destination. In path determination process a routing algorithm find out and maintain routing tables that has routing information of the network on that data packet has to transfer. The information of route in routing tables varies from one routing algorithm to another. The routing tables to be filled with the entries such as IP-Address prefix and the next hop. Destination/next hop associations of routing table tells the router that a desire location can be reached optimally by sending the data packet to a router in the network represents the next hop on its way to the find the destination and IP-Address prefix specifies destinations for which the routing entry is valid. The routing protocol may be classified into two types such as static routing protocol and dynamic routing protocol. Fore More info Https://www.ThesisScientist.com

39. Static routing refers to the routing mechanism being stated as manually or statically, in the router. Static routing maintains a routing table usually it is written by a networks administrator. The routing table never depend upon the situation of the network status, i.e., whether the destination node is active or not. Dynamic routing refers to the routing procedure that is being learnt intelligently by an interior routing protocol or exterior routing protocol. Such type routing primarily depends on the situation state of the network i.e., the routing table is affected by the activeness of the destination. 2.2 Routing in Mobile Ad hoc Networks A Mobile Ad-Hoc network is self-organizing and self-configuring multi-hops wireless and decentralizes networks, where the state of the structure of the network changes dynamically. This is mainly cause of the mobility of the nodes in the network; nodes in the networks always try to utilize the same random access wireless channel of the network, cooperating in an intimate manner to engaging themselves in the multi-hop forwarding. The mobile nodes in the network only does not acts as a hosts, but also as routers that route data to from the others nodes in network. In mobile ad-hoc networks there is no need of pre existing infrastructure support as wireless networks, and since a destination node might be out of range of a source node to transferring data packets; so that there is need of a routing procedure. This is always ready to find a path so as to forward the data packets appropriately between the source node and the destination node. Within a cell, a base station can reach to all mobile nodes without using a routing via broadcast in common scenario of the networks. In Ad-Hoc network each node must be able to forward the data packets for other nodes. This always creates additional Fore More info Https://www.ThesisScientist.com

40. problems due to dynamic nature of topology which is unpredictable connectivity changes problems along with the nature of dynamic topology which is unpredictable connectivity changes. 2.3 Properties of Ad-Hoc Routing protocols The properties that are desirable in Ad-Hoc Routing protocols are: i). Distributed operation: This is a property of Ad-Hoc routing protocol in this the protocol should be distributed. It should not be dependenton a centralized administrator that controls the network. The dissimilarity is that the nodes in an Ad-Hoc network is able to leave or enter in the network very easily because of mobility the network can be partitioned. ii). Loop free: The overall performance of the network can be improved with better selection of the protocol. The routing protocol shouldbeassurance that the routes supplied are loop free and these avoid any misuse of the bandwidth or CPU consumption. iii). Demand based operation: To minimize the control overhead in the network it should not misuse the network resources, protocol should be reactive in nature and protocol should react only when it is needed and should not periodically broadcast control information. Fore More info Https://www.ThesisScientist.com

41. iv). Unidirectional link support: The radio environment is a cause of formation ofan unidirectional links. Even not only the bi-directional links improves the routing protocol performance along with utilization of these links and. v). Security: The radio environment is especially vulnerable to impersonation attacks so it becomes more important to ensure the wanted behavior of the routing protocol we have to need some sort of security issues. Authentication and encryption is a way of delivery data packets and problem is that here within distributing the keys among the nodes in the ad-hoc network. vi). Power conservation: The nodes in the Ad-Hoc network may be the laptops and thin clients such as PDA that are limited to the battery power and therefore uses some standby mode to save the power. Therefore, it is very important that the routing protocol has to support for these sleep modes. vii). Multiple routes: To reduce the number of reactions in the topological changes and congestion multiple routes can be used for data packet delivery. If one route becomes invalid, it is possible that another stored route could be still valid and thus saving the routing protocol from initiating another route discovery procedure. viii). Quality of Service Support: Some sort comings of Quality of service is necessary toincorporate into the routing protocol. This helps us to find that what these networks will be used for. It could be for instance real time traffic support. Fore More info Https://www.ThesisScientist.com

42. For more than two decades, the extensive research work has been done in this area. This chapter will discuss the various techniques and ways, proposed by different researchers for preventing and avoiding different attacks and malicious nodes in AODV and improve the packets delivery ratio in the network, end to end delay and throughput. Many researchers measure the performance of AODV in malicious environment. In this we will classify the field of attacks and counter measures and measure the performance on the basis of different parameter like delivery ratio, end to end delay etc. we will discuss the applicability of this field vividly in current network age with issues and challenges faced during over coming them. 2.4 Classification of Routing Protocols Classification of routing protocols in Mobile Ad-Hoc Network can be made in several ways, but most of these are done depending on routing strategy and network structure. We can classify some routing protocols as a flat routing, hierarchical routing and geographic position assisted routing depending on the structure of the network. According to the routing strategy routing protocols can be classified as Table-driven and source initiated. 2.4.1 Flat Routing Protocols Flat routing protocols are divided mainly into two classes such as first one is the Proactive Routing (table driven) protocols and second one is the reactive (on-demand) routing protocols. There is one thing in general for both protocol classes is that every node participating in routing play an equal role. Further they have been classified after Fore More info Https://www.ThesisScientist.com

43. their design principles; proactive routing is mostly based on link-state, while on-demand routing is based on DV (distance-vector). 2.4.1.1 Pro-Active / Table Driven routing Protocols Proactive MANET protocols are also referred as table-driven routing protocols and will actively determine the network layout. Through a regular exchange of topology of the network packets between the nodes of the network, at every single node an absolute scenario of the network is maintained. There is hence minimal delay in determining the route to be taken. When the routing information becomes worthless quickly its become important for the time-critical traffic, there are many short-lived routes that can be determined and they are not used before they turn invalid. The amount of traffic overhead generated when evaluating these unnecessary routes is another drawback resulting from the increased mobility. The portion of the total control traffic consists of actual practical data is further decreased. Lastly, most of the routing information is considered redundant if the nodes transmit infrequently. However, the nodes continue to expend energy by continually updating these unused entries in their routing tables as mentioned. In this situation energy conservation is very important factor in the MANET system design. Therefore, this excessive expenditure of energy is not desired in this case proactive protocols in MANET works better. This protocol has low node mobility, where the nodes transmit data frequently. The proactive routing protocols in MANET include; Optimized Link State Routing (OLSR). Fore More info Https://www.ThesisScientist.com

44. Destination-Sequenced Distance Vector (DSDV) Fish-eye State Routing (FSR). Cluster-head Gateway Switch Routing Protocol (CGSR). 2.4.1.2 Reactive (On Demand) protocols Portable notebooks nodes, palmtops or even mobile phones usually consist of wireless Ad-Hoc networks. This portability also brings a significant issue of mobility. This is a key issue in The Ad-Hoc Networks. Due to the mobility of the nodes the topology of the network continuously changes. This is not a easy task to keeping track of this topology, and too many resources may be consumed in signaling. These are based on the design that there is no point on trying to have a scenario of the entire network topology, since it constantly changes. Instead, whenever a node looks for a route to a destination, it initiates route discovery process, for discovering out a pathway reactive protocol try to set up routes on-demand. The basic purpose of routing protocol is to establish such a route, whenever any node wants to communicate with another node and it has no route. This kind of protocols is usually based on flooding of the message on the network with RREQ and RREP messages. By the help of Route Request message the route is discovered from source to target node and as well target node receives a RREQ message it send RREP message for the confirmation for the route has been established. This kind of protocol is usually very effective on single-rate networks. Usually, it minimizes the number of hops for the selected path. However, on multi-rate Fore More info Https://www.ThesisScientist.com

45. networks, the number of hops is not as important as the throughput that can be obtained on a given path. The different types of On Demand driven protocols are: Ad-Hoc On Demand Distance Vector routing protocol (AODV) Dynamic Source routing protocol (DSR) Temporally ordered routing algorithm (TORA) Associativity Based routing protocol (ABR) Signal Stability-Based Adaptive Routing protocol (SSA)  Location-Aided Routing Protocol (LAR) 2.4.1Hybrid Routing Protocols Both proactive and reactive routing protocols works better in the oppositely different scenario and hybrid method uses both. It is used to find a balance between both protocols such proactive operations to be restricted to small domain, whereas, reactive protocols are used for locating nodes that are outside the domains. Examples of hybrid protocols are: Zone Routing Protocol, (ZRP) Wireless Ad hoc Routing Protocol, (WARP) 2.4.3Hierarchical Routing Protocols As the size of the wireless network increases produce too much overhead for the MANET. In this circumstance a hierarchical solution may be preferable and these are: Hierarchical State Routing (HSR). Fore More info Https://www.ThesisScientist.com

46. Zone Routing Protocol (ZRP). Cluster-head Gateway Switch Routing Protocol (CGSR). Landmark Ad Hoc Routing Protocol (LANMAR). 2.4.4Geographical Routing Protocols There are two approaches to geographic mobile ad hoc networks: 1.Actual geographic coordinates (as obtained through GPS – the Global Positioning System). 2.Reference points in some fixed coordinate system. An advantage of geographic routing protocols is that they prevent network-wide searches for destinations. If the recent geographical coordinates are known then control and data packets can be sent in the general direction of the destination. This trim downs control overhead in the network. A disadvantage is that all nodes must have access to their geographical coordinates all the time to make the geographical routing protocols useful. The routing updates must be done faster in compare of the network mobility rate to consider the location-based routing effective. This is because locations of nodes may change quickly in a MANET. Examples of geographical routing protocols are: Geo Cast (Geographic Addressing and Routing) DREAM (Distance Routing Effect Algorithm for Mobility) GPSR (Greedy Perimeter Stateless Routing)  Fore More info Https://www.ThesisScientist.com

47. 2.5 AD HOC ON-DEMAND DISTANCE VECTOR (AODV) The Ad hoc On-Demand Distance Vector (AODV) algorithm enables dynamic, self- starting, multihop routing between participating mobile nodes wishing to establish and maintain an ad hoc network. AODV allows mobile nodes to obtain routes quickly for new destinations, and does not require nodes to maintain routes to destinations that are not in active communication. AODV allows mobile nodes to respond to link breakages and changes in network topology in a timely manner. The operation of AODV is loop- free, and by avoiding the Bellman-Ford "counting to infinity" problem offers quick convergence when the ad hoc network topology changes (typically, when a node moves in the network). When links break, AODV causes the affected set of nodes to be notified so that they are able to invalidate the routes using the lost link. One distinguishing feature of AODV is its use of a destination sequence number for each route entry. The destination sequence number is created by the destination to be included along with any route information it sends to requesting nodes. Using destination sequence numbers ensures loop freedom and is simple to program. Given the choice between two routes to a destination, a requesting node is required to select the one with the greatest sequence number. Fore More info Https://www.ThesisScientist.com

48. Figure 2.1 A possible path for a route reply if A wish to find a route to J Route Requests (RREQs), Route Replies (RREPs), and Route Errors (RERRs) are the message types defined by AODV. These message types are received via UDP, and normal IP header processing applies. So, for instance, the requesting node is expected to use its IP address as the Originator IP address for the messages. For broadcast messages, the IP limited broadcast address (255.255.255.255) is used. This means that such messages are not blindly forwarded. However, AODV operation does require certain messages (e.g., RREQ) to be disseminated widely, perhaps throughout the ad hoc network. The range of dissemination of such RREQs is indicated by the TTL in the IP header. Fragmentation is typically not required. As long as the endpoints of communication connection have valid routes to each other, AODV does not play any role. When a route to a new destination is needed, the node broadcasts a RREQ to find a route to the destination. A route can be determined when the RREQ reaches either the destination itself, or an intermediate node with a 'fresh enough' route to the destination. A 'fresh enough' route is a valid route entry for the destination whose associated Fore More info Https://www.ThesisScientist.com

49. sequence number is at least as great as that contained in the RREQ. The route is made available by unicasting a RREP back to the origination of the RREQ. Each node receiving the request caches a route back to the originator of the request, so that the RREP can be unicast from the destination along a path to that originator, or likewise from any intermediate node that is able to satisfy the request. Nodes monitor the link status of next hops in active routes. When a link break in an active route is detected, a RERR message is used to notify other nodes that the loss of that link has occurred. The RERR message indicates those destinations (possibly subnets) which are no longer reachable by way of the broken link. In order to enable this reporting mechanism, each node keeps a "precursor list", containing the IP address for each its neighbors that are likely to use it as a next hop towards each destination. The information in the precursor lists is most easily acquired during the processing for generation of a RREP message, which by definition has to be sent to a node in a precursor list If the RREP has a nonzero prefix length, then the originator of the RREQ which solicited the RREP information is included among the precursors for the subnet route (not specifically for the particular destination). A RREQ may also be received for a multicast IP address. In this document, full processing for such messages is not specified. For example, the originator of such a RREQ for a multicast IP address may have to follow special rules. However, it is important to enable correct multicast operation by intermediate nodes that are not enabled as originating or destination nodes for IP multicast address, and likewise are not equipped for any special multicast protocol processing. For such multicast-unaware nodes, processing for a multicast IP address as a destination IP address MUST be carried Fore More info Https://www.ThesisScientist.com

50. out in the same way as for any other destination IP address. AODV is a routing protocol, and it deals with route table management. Route table information must be kept even for short-lived routes, such as are created to temporarily store reverse paths towards nodes originating RREQs. AODV uses the following fields with each route table entry: Destination IP Address Destination Sequence Number Valid Destination Sequence Number flag Other state and routing flags (e.g., valid, invalid, repairable, being repaired) Network Interface Hop Count (number of hops needed to reach destination) Next Hop List of Precursors Lifetime (expiration or deletion time of the route 2.6 AODV Terminology Active route: It is a route towards a destination that has a routing table entry that is marked as valid. Only active routes can be used to forward data packets. Broadcast: Broadcasting means transmitting to the IP Limited Broadcast address, 255.255.255.255. A broadcast packet may not be blindly forwarded, but broadcasting is useful in enabling dissemination of AODV messages throughout the ad hoc network. Fore More info Https://www.ThesisScientist.com