International Journal of Advanced Research in Computer Science and Software Engineering

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1 ISSN: X International Journal of Advanced Research in Computer Science and Software Engineering Research Paper Available online at: Reactive Address Allocation and Duplicate Address Detection Techniques in MANET 1 Vishesh Kumar Singh, 2 Anubhav Kumar Tiwari, 3 Ramjee Dixit 1 Computer Science & Engineering Dept. Shobhit Institute Of Engineering & Technology, Gangoh 2 Electronics & Communication Dept. Shobhit University, Meerut 3 Computer Science & Engineering Dept. Shobhit Institute Of Engineering & Technology, Gangoh Abstract: A Mobile Ad Hoc Network (MANET) consists of a set of identical mobile nodes communicating with each other via wireless links. The network's topology may change rapidly and unpredictably. Typically, dynamic configuration in a wired network is accomplished by using the Dynamic Host Configuration Protocol (DHCP). In mobile ad hoc networks, however, there is no fixed infrastructure and nodes do not have access to a centralized server to acquire IP addresses. Further, due to node mobility, network partitions and merges are frequent occurrences. Such events create the possibility of duplicate addresses within the network. Therefore, a centralized approach cannot be applied in these networks; a distributed and dynamic mechanism is needed for nodes to acquire and maintain a unique IP address in mobile ad hoc networks. In this paper we present a reactive address allocation scheme for dynamic IP address assignment with DAD for address conflict detection. Our solution uses the concept of reactive allocation and takes into consideration the previously unsolved issues like partitioning and merging and abrupt departure of nodes from the system. Our solution also show the binding nature of its technique with any of the routing protocols types i.e. reactive or proactive routing protocols. KEYWORDS: MANET, DAD, NDAD, AUTO CONFIGURATION, IP ADDRESS. MAIK, BAIK I. INTRODUCTION MANET (Mobile Ad Hoc Networks) is a wireless network in which all movable nodes can communicate with each other without depend on a fixed infrastructure. Here packet forwarding and routing is achieved by intermediate nodes. In routing protocols, a routing path is acquired when a source desires to send data packets to destination. In order to send and receive packets between two nodes, they should have their unique address in the network. Since IP is also used in MANETs, a unique IP address should be assigned to each node. Therefore, IP address auto configuration schemes have been developed to remove the overhead of manual configuration. In general, we can categorize the IP assignment solutions to be either reactive or proactive. Reactive protocols require a consensus among all the nodes of the network on the new IP address that is to be assigned, whereas in the proactive approach, each node can independently assign a new IP address without asking permission from any other node in the network. Mobility is one of the reasons for partitioning of the network. When a node having unique IP address in one partition, moves into another partition, there may arise a chance of duplication of the IP address. Since, IP address has to be unique, address conflicts need to be detected through a DAD (Duplicate Address Detection) procedure. Duplicate Address Detection (DAD) is the methodology introduced for monitoring the repetition of IP addresses by the individual nodes itself. In this paper, we propose a reactive IP address assignment scheme with DAD for address conflict detection for the MANET. The network configuration parameter that is required to be unique for each node in the network is its IP address. Our distributed protocol with DAD mechanism ensures that no two nodes in the MANET acquire the same IP address. We describe enhancements to the solution that can handle problems that may arise due to node failures, message losses, mobility of the nodes, or multiple concurrent initiations of node configuration, and network partitioning and merger. The solution is divided in two phases. First phase deals with the Duplicate Address Detection technique in which we have introduced two new terms for two nodes i.e. MAIK (main address information keeper), & BAIK (backup address information keeper). Both nodes are used DAD and for keeping the state information of the network including network identifier, IP address of all the nodes with their lifetime. This information is helpful in network partitioning and merging and makes the solution to be bind with any of the routing protocols type s i.e. reactive or proactive routing protocols. Second phase deals with the Reactive Address Allocation Technique in which a newly node proposes a candidate IP address for his IP address assignment. If the proposal is accepted by all the nodes that are part of the MANET, the proposed address is assigned to the newly arrived node. Otherwise, another candidate IP 2012, IJARCSSE All Rights Reserved Page 281

2 address is chosen and the process is repeated (for a finite number of times). Every node has to register with the MAIK which confirms its IP address allocation through acknowledgement and start its lifetime. At the end of life time each node has to re-register itself for further communication. When merging of network occurs then MAIK is responsible for detecting IP address conflict. The newly joined node becomes the MAIK and previous MAIK becomes the BAIK. MANET nodes communicate with each other by exchanging IP packets. As the corresponding nodes may not be directly reachable from each other, intermediate nodes have to forward IP packets. Hence, MANET nodes can behave as routers would towards IP packets for which they are neither the source, nor the destination. For simplicity, we will assume that the IP address block from which nodes are to be assigned their IP addresses is known in advance. Purely for the sake of illustration, we could consider the MANET to be a private IP version 4 network using any of the following private address blocks: , , [2]. The rest of this paper is organised as follows. Section II presents the previous works of the IP-address assignment in the MANET. Section III presents our proposed scheme. Discussion & Results are shown in Section IV. We draw our Conclusion in Section V. Finally, future scope in Section VI. one that updates the routes constantly, but with a reactive one there will be nodes that could never detect the duplicity of IP addresses. It does not add additional overhead to the routing protocol, but on the other hand, it really adds to the overhead by sending always the key along with the IP address. In the Strong Duplicated Address Detection (DAD) scheme [5] the node chooses two IP addresses: temporary and tentative. It will only use the temporary address for the initialization while it detects if the tentative one is unique or not. The detection method consists of sending a message ICMP destined directly to this address. If it receives a response, this IP address is being used so the process will be resumed. If it does not receive a response, the message will be sent a certain number of times to make sure that the address is unique. It would not work for temporary disconnections or losing of the network. Moreover, when the network is long and only a few free IP addresses remain, it increases the overhead until it finds a unique IP address. In Address auto-configuration with address Reservation and Optimistic duplicated address Detection (AROD) [6], the address reservation is based on the existence of nodes that have an IP address reserved to deliver it to the new nodes that enter. Two types of nodes will exist: 1) Agents type 1 with a reserved IP address, apart from the IP address that has its network interfaces. When a node joins the network, this reserved IP will be assigned to it immediately. 2) Agents type 2, which do not have reserved IP addresses. If a node that joins newly asks one of these for an IP address, this node borrows the reserved address of one of its neighbours who is of type 1, and it is assigned to the new one immediately. If the possibility of changing the reserved IP address number to the node type, number increases, the latency of IP address assignment is minor, but on the contrary the overhead increases due to having had to undergo more DAD processes, and vice versa. HCQA [7] is a dynamic address configuration protocol for mobile ad hoc networks that provides address assignment to mobile nodes during the formation and maintenance of a network. The protocol assigns unique addresses and can be combined with a variety of routing schemes. Further, the address authority aids in the detection of duplicate addresses and handles address resolution after network partitions and merges. It has two main problems, firstly the overhead produced by the SDAD process and periodic messages of Address Authority, and secondly, the network depends on a central entity with which all nodes must communicate directly in order to register its IP address, so that much latency is added at the joining of nodes to the network. In Zeroconf [8] problem of node configuration in the absence of servers dedicated to such a task has been the focus of the Zeroconf working group of the Internet Engineering Task Force (IETF). However, the solutions proposed by the Zeroconf working group are not directly applicable to MANETs. Zeroconf solutions are intended to assign link-local unique IP addresses to nodes connected in the following topologies: 1) a single network segment to which all nodes are connected so that each can directly communicate with the other II. RELATED WORK In an autonomous ad hoc mobile network the nodes can be uniquely identified by an IP address with the only premise that this address must be different from that any other node in the network. The configuration process is the set of steps through which a node obtains its IP address within the network. There are three mechanisms [1] to set addresses: Stateless and Stateful and Hybrid. Instead of the assignment of addresses by a second entity, stateless auto-configuration allows the nodes to construct addresses by themselves, usually based on a hardware ID or a random number. Mobility is one of the reasons for partitioning of the network. When a node having unique IP address in one partition, moves into another partition, there may arise a chance of duplication of the IP address. Since, IP address has to be unique, address conflicts need to be detected through a DAD (Duplicate Address Detection) procedure. Duplicate Address Detection (DAD) is the methodology introduced for monitoring the repetition of IP addresses by the individual nodes itself. [3] Presents the importance of detection of IP address conflicts and different schemes introduced for detection. Weak DAD, presented in [4], is an approach to prevent a packet from being routed to a wrong destination, even if duplicate addresses exist. Nodes in the network are identified not only by the IP address, but additionally by a key, which can be based on a hardware ID or a random number. If a node receives a packet containing an IP address that is stored in its routing table, but with a different key, an address conflict is detected. It will only work with the proactive 2012, IJARCSSE All Rights Reserved Page 282

3 through link-layer broadcasts and multicasts. 2) Multiple network segments connected to the same router. These two topologies capture only a small subset of possible MANET topologies. All MANET nodes are not guaranteed to be reachable from each other through at most one intermediate node. Hence, link-level broadcasts are not guaranteed to reach all MANET nodes. As a result, duplicate address detection (DAD), as described in the Zeroconf solutions is not feasible. In MANETconf [9] a new node entering the MANET request for configuration information from its neighbours. One of these neighbours initiates the IP address allocation process for the new node. This approach handles network partitioning and subsequent merging. Mohsin and Prakash [10] propose a stateful protocol which uses Multiple Disjoint Allocation Tables. In this approach every node has a disjoint set of IP addresses that can be assigned to new nodes, is said that as node owns these pool of IP addresses hence no quorum is required to make a decision. This approach uses a proactive scheme for dynamic allocation of IP addresses in MANETs. This protocol employs the approach described in MANETconf to solve network partitioning. The major drawback of this protocol is that the synchronization depends on the existence of a reliable broadcast and such a thing does not exist in a distributed mobile environment, thus one can question the robustness of this protocol. An improvement of [10] can be found in [11], where Thoppian and Prakash propose a dynamic address assignment based on a so-called buddy system that manages mobility of nodes during address assignment, message loss, and network partitioning and merging. However, the IP address allocation can generate a high overhead of control messages while it does a global search and the address recovery (to avoid missing addresses) requires diffusion messages by a flooding process. In addition, union and partition may incur in high overhead because of the global nature of this protocol. Extensible MANET Auto-configuration Protocol (EMAP) [12] is based on the idea of a protocol of REQUEST/REPLAY messages. The main advantage of this protocol is the possibility of doing it extensible, i.e., it can include new functionalities in the future that are analyzed in a theoretical way, such as Domain Name Server (DNS). The route discovery mechanism among nodes is similar to the Ad Hoc On-Demand Distance Vector (AODV) [13] protocol. The protocol in [14] proposes a scheme where the nodes are classified into coordinator and common nodes. The first coordinator assigned to initiate the IP address assignment is the so-called C-root. The coordinators manage the IP address pool and they are responsible for assigning an IP address to a node which has just joined the network. The nodes that wish to join the network will interchange HELLO messages to find the coordinator node nearest and to obtain a new IP address from that coordinator node. To maintain the IP address pool efficiently, the coordinator nodes are distributed in a tree topology called C-tree by exchanging HELLOs. This protocol does not consider network partition and merging. In D2HCP [15] protocol each node is responsible for managing a range of addresses. When a new node wants to begin participating in the network, one of the nodes within the network gives half of its address range to the new node. In the case of any adjacent node not having free addresses, but free addresses do exists, a request to a network node that has free addresses is done. In this operation mode is based on distributed nature of the protocol. To keep updated information about free addresses owned by each node, the traffic of control packets from OLSR [16] protocol. It does not consider network partition and merging and this protocol have been designed to work together with OLSR which is proactive in nature. This paper presents an address auto configuration protocol using IPv4 to provide address assignment to mobile nodes during the formation and maintenance of a mobile ad hoc network. The protocol consists of address assignment, duplicate address detection, and address maintenance. The characteristics of the proposed approach are: 1) _nodes can obtain IP addresses without a fixed centralized server; 2) _unique addresses are assigned throughout the lifetime of network; 3) _the protocol handles problems that may arise due to network partitions and merges; 4) _the protocol can be integrated with both reactive and proactive routing protocols. III. PROPOSED WORK In this paper, we propose a reactive IP address assignment scheme with DAD for address conflict detection for the MANET. The solution is divided in two phases: A. PHASE I: DUPLICATE ADDRESS DETECTION A major issue of address auto configuration is Duplicate Address Detection (DAD). Duplicate addresses may arise during the initialization of a group of nodes since nodes may be multiple hops away and cannot hear each other directly. Also during merging two nodes may acquire same address. Figure 1 shows an example of the existence of duplicate addresses and the resulting erroneous routing. Nodes X and Y obtain the same IP address, x, independently from different networks. A source node in network 1 initiates a session and communicates with node X through the routing path indicated by arrow (1). This path has a length of two. When the two networks move towards each other and subsequently merge, node Y enters the direct transmission range of the source node. Hence, if proactive routing protocols are used, after receiving the periodic routing information update, the source node will update its routing entry for IP address x to the direct path to node Y with path length of one; if reactive routing protocols are used, a new route discovery process will also result in the route to address x to the new path indicated by arrow (2). Thus erroneous routing prevents the source from communicating with the correct destination. So, DAD is very necessary. 2012, IJARCSSE All Rights Reserved Page 283

4 As we have seen WDAD [4] and SDAD [5] that both have their own limitations. In [4] if a new node joins the network without knowledge of the routing information and the identifier, it cannot distinguish these two nodes only by IP addresses. Hence this will lead to erroneous routing. In [5] if a node is disconnected for a long time, it will not receive the packet; this can be treated as partition. So due to this we have defined a new DAD called as a Normalize DAD. Figure 1: Example of duplicate addresses and erroneous routing. Node X and Y have the same IP address x. Erroneous routing occurs when these two networks merge. be utilized. This unique network identifier is used to detect Merging and Partitions. 3) First Level of duplicate address detection: Every node entering in the network need an IP address for the communication. Suppose a node enters in network and randomly choose a candidate IP address, because it is reactive procedure it have to take permission from each node for the selecting the candidate IP address for itself. The node then creates Address Request (AREQ) by placing its candidate IP address as well as its hardware address. Then it broadcasts this AREQ message. AREQ messages also include a sequence number associated with the candidate IP address to indicate the number of times the node has attempted DAD on this address. This prevents nodes from processing a single AREQ message multiple times. When a mobile node receives an AREQ message, it creates a reverse route entry for the node indicated by the hardware address in the AREQ. The node then checks whether its own IP address matches the requested address in the AREQ. If the node's IP address does not match the requested address, it rebroadcasts the packet to its neighbours. If the new node receives any reply with AREP message then it will come to know that the candidate address is being used by some other node and it will select other candidate address and the process will repeat. 1) Normalize DAD (NDAD): In NDAD the MAIK and BAIK nodes are responsible for the detection of duplicate address, even in the procedure it goes with double detection phase within a single step, which makes it more reliable. The NDAD is used in address allocation phase with ease which helps it in dynamically assigning of address without duplicate address. How MAIK and BAIK are elected, how they are useful in detecting duplicate address is given in following section. 2) Election of MAIK & BAIK: MAIK stands for main address information keeper and BAIK stands for Backup address information keeper. These two nodes are responsible for maintaining the node state of all nodes in the network (i.e. network identifier, IP address of all the nodes with their lifetime etc.). The new node joining the network after registration becomes MAIK and the previous MAIK becomes BAIK. In case of only one node in the network it is MAIK. Every new node is being registered with MAIK, it store the state of new node, start the life time for it and acknowledge the new node. After the acknowledgment to the new node the whole state information of all nodes in the network is sent from old MAIK to the new node which is the new MAIK. To obtain a unique network identifier, the identifier can, for instance, be set to the MAC address of the MAIK; any other mechanism that can generate unique IDs can also 4) Second Level of duplicate address detection: When MAIK will receive the AREQ message broadcasted by the new node with its candidate address then it will check from its list that whether the selected candidates address is used by some other nodes or not. If used then it sends AREP message to the node and the new node will select another candidate address. This is very beneficial because, suppose in the absence of MAIK the node using the candidate address is temporarily disconnected or its messages losses then it will unable to sent the AREP to the new node and new node will assign the candidate IP address as its IP address. And further when the old node with same address re-connected with the network it can create erroneous routing. So, MAIK ensure the second level of DAD. 5) Third level of duplicate address detection: Now after acquiring the candidate IP address it starts it ask_time and waits for ask_registration message from MAIK. MAIK sends ask_registration unicast message directly at candidate IP address, if any how the node using the candidate IP address AREP message as well as MAIK AREP message does not reach to the new node then even duplicate address will be detected since the new node as well as the node using that IP address both will reply with Registration Request message. The old node and new node will send his IP address with its MAC address with their required life time. Now MAIK can match with IP address and MAC address with its address list 2012, IJARCSSE All Rights Reserved Page 284

5 and will send AREP message to new node. If the requested IP address included in the AREP message matches its candidate address, this indicates that another node within the ad hoc network is currently using that IP address. And new node will select another IP address. 6) Synchronization of MAIK & BAIK: In [7] the major problem was the overhead produced by the SDAD process and periodic messages of Address Authority to synchronize it. The election procedure also causes overhead since they have to send broadcast at regular interval of time otherwise each node will declare itself as AA. The procedure is also dependent on one node i.e. AA. This overhead has been removed in our solution since no specific node remains MAIK & BAIK so the solution is also not dependent on one node. To synchronize the network for MAIK & BAIK presence and to make aware of the unique network identifier to all the nodes for detecting network portioning and merging no special broadcast message is required. Each time when new node will join and registered itself then only it have to broadcast its unique network identifier so that each node update itself about new MAIK and which network id they belong to. 7) Unavailability of MAIK & BAIK: Synchronization of MAIK and BAIK is necessary during crashes of these or both nodes for duplicate address detection. MAIK and BAIK will unicast an empty message for their presence. MAIK will send empty message and BAIK have to acknowledge him. a) When MAIK fails then the BAIK will not receive empty message, after a specific duration of wait_time, (wait time > threshold no. Of minimum attempt * total_time_ synchronization in one unicast ) it will declare itself as MAIK. It sets the new network identifier to be its own MAC address and broadcasts an advertisement message indicating this new value. The mobile nodes within the network update their record of the network identifier. It selects the new BAIK having largest lifetime and broadcast address list. BAIK will keep the list and the other nodes whose address is not present in list will register themselves with the new MAIK. b) When BAIK fails MAIK will not receive acknowledgement and after a threshold number of attempt it will follow the above a) section procedure. c) When both the node fails then, when any nodes lifetime expires it tries to re register itself with the MAIK and due to unavailability of MAIK after a threshold number of try it will declare itself as MAIK. It sets the new network identifier to be its own MAC address and broadcasts an advertisement message indicating this new value. It broadcast empty address list and all node will register with it. Now it selects a BAIK having largest life time and sends the address list. The proposed address auto configuration protocol enables nodes to select unique IP addresses, and is able to detect address duplicates using above NDAD scheme after network merges. 1) MANET & Node Initialization: A node entering a network, broadcast Address Request (AREQ) by placing its randomly chosen candidate IP address as well as its hardware address for the reply. Node starts its reply_timer, if reply_timer expires and he does not get any AREP message, he repeats the step for threshold no. of time (off course NDAD described above is taking place for duplicate address detection) than it conclude that he can select the address for the communication. But before registration it cannot use it for communication, so it waits for MAIK ask_registration unicast message sent directly at his acquired IP address, if any how the node using the candidate IP address AREP message as well as MAIK AREP message does not reach to the new node then even duplicate address will be detected as described in(iii.a.5). And new node will repeat the above process again. If he does not receive any ask_registration message for ask_time where ask_time> n*ask_registration_time then he will come to know that he is the only node in the network and he will initialize the MANET and declare itself as MAIK. 2) Registration with MAIK: After going all the three level of duplicate address detection the new node with his acquired IP address, its MAC address, as well as a requested lifetime for the IP address unicasts a Registration Request to MAIK. The MAIK adds the information for this node to its address list and unicasts a Registration Reply to the node indicating whether the registration was successful. Upon success, the Registration Reply indicates the approved lifetime for the address. Now the old MAIK will become BAIK and send the address list with its state information to the new registered node which is now new MAIK. After becoming MAIK he has to broadcast its unique network identifier so that each node updates itself about new MAIK and which network id they belong to. The old BAIK will come to know with this broadcast that he is no longer been BAIK. 3) Detecting partition and merging: When a network becomes partitioned, both the MAIK and BAIK may exist in the same partition, while no MAIK or BAIK exists in other partitions. It is also possible for the MAIK and BAIK to exist in different partitions. In any of these scenarios, the selection and maintenance mechanism described in section III.A.7 enables the different partitions to obtain both a MAIK and a BAIK within a short time. Thus, after a network partition, each partition will obtain its own MAIK & BAIK, and a unique network identifier assigned to the B. PHASE 2: ADDRESS ALLOCATION SCHEME MAC address of the MAIK. If a node partitioned from the network then after a end of life time it has to register with MAIK and if not register itself with MAIK then it 2012, IJARCSSE All Rights Reserved Page 285

6 detects Volume 2, Issue 7, July 2012 would be considered as partition. If these partitions merge, they are regarded as different networks and can be distinguished by their unique identifiers. To detect a network merge, a unique identifier for each individual network can be utilized. The idea of the unique identifier is similar to that described in MANETconf [9]. When two previously distant nodes X and Y come within communication range of each other, they exchange their unique identifier identities. If the received unique identifier identity is different from ix s own unique identifier identity then X i the merger of partitions. Node Y j also detects the merger at the same time. Now node X and Y will sent a unicast message to their respective MAIK for the new unique identifier and MAIK of different networks detects merging. The MAIK then exchange their address lists to detect duplicate addresses. If duplicate addresses exist, the MAIK with the lower network identifier notifies the node from its network with the duplicate address that it should select a new address. To avoid erroneous routing, this notification message is broadcast, including the node address and the network identifier. This enables the correct node to respond. Also, after the address lists are exchanged, the MAIK agree on a single MAIK for the merged network by selecting the MAIK with the highest network identifier. The advantage of this approach is that when networks merge, change of IP addresses is only needed when there is duplication. Only the MAIK are responsible for duplicate address detection; other nodes do not need to perform DAD themselves when merge happens. So it can handle the network partitioning and merging very well. 4) Algorithm for address allocation: Step1: New node selects a random IP address. Step2: Broadcasts AREQ message. Step3: Start reply_timer, wait for AREP message. Step4: If reply_timer expires repeat Step3 for threshold number of time (if no AREP is received) Step5: Acquire IP address (if no AREP received) Step6: Start ask_timer and wait for ask_registration message where ask_time> n*ask_registration_time (n is threshold number of attempt from MAIK and ask_registration_time is total time for one registration) Step7: If ask_time expires then declare itself as MAIK. Set its MAC address as unique network identifier Otherwise, Send Request Register message to MAIK and when acknowledged by MAIK, declare itself as MAIK and broadcast new unique network identifier. Old MAIK will be BAIK now. Step8: If new node enters repeat steps from step 1. 5) Modular Architecture of Proposed Scheme: Figure 2: Architecture of proposed scheme IV. DISCUSSION AND RESULT Here we are discussing previous schemes drawback and how this paper removes those drawbacks. A. SPECIFIC ROUTING PROTOCOL DEPENDENCE In [4], [9], [10], [11], and [15] the duplicate address detection is done by Proactive Routing Protocol. They all are totally dependent on proactive scheme in which each node maintains a routing table with an entry for every other node in the network. B. IGNORANCE OF MERGING AND PARTITION ISSUE In [6], [12], [14], and [15] the major issue of MANET i.e. network portioning and merging is not discussed. [5] Does not work well for temporary disconnections. In [8] DAD is not possible. C. OTHER ISSUE In [7] has one main problems, the overhead produced by the SDAD process and periodic messages of Address Authority creates overhead. D. SOLUTION 1) This paper discusses major issue of network merging and partitioning which is very necessary in real world scenario. 2) In the solution DAD is also possible and it also works well for temporary disconnection of nodes. 3) Binding: It is not routing protocol specific. It can work with both Reactive Routing protocol and Proactive Routing protocol. In Proactive Routing protocol because nodes know the IP address of each node in the network, when new nodes join an established network, they do not need to perform duplicate address detection throughout the whole network. Instead, the proactive connectivity information 2012, IJARCSSE All Rights Reserved Page 286

7 exchange can be leveraged for the address auto configuration protocol to perform the duplicate address detection. When a node initializes, it locally broadcasts an AREQ message by limiting the hop count of the AREQ to one. Because the neighbours know the IP address of every other node, they reply with an AREP if the requested address is already in use. The node then selects another candidate address and sends another AREQ. In reactive routing protocols, mobile nodes do not maintain routes to each known node in the network, nor do they maintain a global view of the network topology. Instead, routes are obtained on-demand and are maintained through route discovery and route maintenance procedures. Because mobile nodes do not know the IP address of every node in the network, they cannot immediately conclude whether there is already some other node in the network using the candidate IP address. So when a node joins an established ad hoc network, in order to detect duplicate addresses within the network, the mechanism described in section III.A is needed. This mechanism conforms to the reactive characteristic of the routing protocols. 4) It also not broadcasts message at regular interval of time, so overhead of that is also reduced. V. CONCLUSION We presented a distributed protocol for dynamic configuration of nodes in MANETs. We have addressed the issue of unique IP address assignment to nodes in MANETs in the absence of any static configuration or centralized servers. This purpose has been achieved through a reactive approach in managing duplicated addresses, as well as through appropriate choices in the use of network resources, in terms of quantity of information stored in the nodes. The protocol assigns unique addresses and can be combined with a variety of routing schemes. Further, the Address Information Keeper aids in the detection of duplicate addresses and handles address conflict after network partitions and merges. The solution has low overheads, and is capable of handling node arrivals & departures. [3] Zahoor ul Huq,S.; Sreenivasa Murthy,K.E.; Sathya Narayana,B.; Kavitha,D., Study of Detection of IP Address Conflicts in MANETS, Global Journal of Computer Science and Technology, April [4] N. H. Vaidya,.Weak duplicate address detection in mobile ad hoc networks, in Proc. of ACM MobiHoc 2002, Lausanne, Switzerland, June 2002, pp [5] Perkins, C., Malinen, J., Wakikawa, R., Belding-Royer, E., and Y. Sun, "IP Address Autoconfiguration for Ad Hoc Networks", I-D draft-ietf-manetautoconf-01.txt, November [6] Kim, N.; Ahn, S.; Lee, Y. AROD: An Address Autoconfiguration with Address Reservation and Optimistic Duplicated Address Detection for Mobile Ad Hoc Networks. Computer. Communication. 2007, 30, [7] Sun, Y.; Belding-Royer, E.M. Dynamic Address Configuration in Mobile Ad Hoc Networks ; Technical Report UCSB ; Department of Computer Science, University at Santa Barbara: Santa Barbara, CA, USA, June [8] S. Cheshire and B. Aboba, Dynamic Configuration of IPv4 Link- Local Addresses, draft-ietf.zeroconf-ipv4-linklocal-03.txt (expires December 22, 2001), Internet Engineering Task Force, Zeroconf Working Group, June [9] S. Nesargi and R. Prakash, MANETconf: Configuration of Hosts in a Mobile Ad Hoc Network, Proceedings of INFOCOM 2002, [10] M. Mohsin and R. Prakash, IP Address Assignment in a Mobile Ad Hoc Network Proc. IEEE MILCOM 2002, Anaheim, CA, Oct2002. [11] Thoppian, M.R.; Prakash, R, A Distributed Protocol for Dynamic Address Assignment in MobileAd Hoc Networks. IEEE Trans. Mobile Comput. 2006, 5, [12] Ros, F.; Ruiz, P.; Perkins, C.E. Extensible MANET Auto- Configuration Protocol (EMAP); Internet Draft; March Available online: 02 (accessed on 25 November 2010). [13] C. Perkins and E. Royer, Ad Hoc On-Demand Distance Vector Routing, 2nd IEEE Workshop on Selected Area in Communications, pp , Feb [14] Sheu, J.P.; Tu, S.C.; Chan, L.H.; A Distributed IP Address Assignment Scheme in Ad Hoc Networks. Int. J. Ad Hoc Ubiquitous Computing. 2008, 3, [15] García Villalba, L.J.; García Matesanz, J.; Sandoval Orozco, A.L.; Márquez Díaz, J.D. Distributed Dynamic Host Configuration Protocol (D2HCP). Sensors 2011, submitted. [16] P.Jacquet, P. Mühlethaler, T Clausen, A. Laouiti, A. Qayyum and L. Viennot Optimized Link State Protocol for Ad Hoc Networks. IEEE INMIC Pakistan VI. FUTURE SCOPE In this paper we present a reactive address allocation scheme for dynamic IP address assignment with DAD for address conflict detection. A major issue that has been ignored in this paper is security. We assume that each node trusts every other node, but this is not always the case, any malicious node can enter in the network which will cause malfunctioning of protocol. So, there is need for further research on security and reliable multicast/broadcast communication in MANETs. REFERENCES [1] Garcia Villalba, L.J.; Garcia Matesanz, J.; Sandoval Orozco, A.L.;Marquez Diaz, J.D., Auto-Configuration Protocols in Mobile Ad Hoc Networks, Sensors 2011, submitted [2] Y. Rekhter, B. Moskowitz, D. Karrenberg, G.J. de Groot, and E. Lear, Address Allocation in Private Internets, RFC 1918, Internet Engineering Task Force, NetworkWorking Group, February , IJARCSSE All Rights Reserved Page 287