Packet Drop Attack Detection Techniques in Wireless Ad hoc Networks: A Review <s> Watch Dog Technique <s> In this paper we describe the current state of the DARPA packet radio network. Fully automated algorithms and protocols to organize, control, maintain, and move traffic through the packet radio network have been designed, implemented, and tested. By means of protocols, networks of about 50 packet radios with some degree of nodal mobility can be organized and maintained under a fully distributed mode of control. We have described the algorithms and illustrated how the PRNET provides highly reliable network transport and datagram service, by dynamically determining optimal routes, effectively controlling congestion, and fairly allocating the channel in the face of changing link conditions, mobility, and varying traffic loads. <s> BIB001 </s> Packet Drop Attack Detection Techniques in Wireless Ad hoc Networks: A Review <s> Watch Dog Technique <s> This paper describes two techniques that improve throughput in an ad hoc network in the presence of nodes that agree to forward packets but fail to do so. To mitigate this problem, we propose categorizing nodes based upon their dynamically measured behavior. We use a watchdog that identifies misbehaving nodes and a pathrater that helps routing protocols avoid these nodes. Through simulation we evaluate watchdog and pathrater using packet throughput, percentage of overhead (routing) transmissions, and the accuracy of misbehaving node detection. When used together in a network with moderate mobility, the two techniques increase throughput by 17% in the presence of 40% misbehaving nodes, while increasing the percentage of overhead transmissions from the standard routing protocol's 9% to 17%. During extreme mobility, watchdog and pathrater can increase network throughput by 27%, while increasing the overhead transmissions from the standard routing protocol's 12% to 24%. <s> BIB002 </s> Packet Drop Attack Detection Techniques in Wireless Ad hoc Networks: A Review <s> Watch Dog Technique <s> Mobile ad hoc networks (MANETs) turn out to be very useful in the current application areas for networks that require ad hoc connectivity as well as mobility. While the MANET routing protocols were designed it was assumed that there is no chance to have a malicious node in the network that does not co operate with each other to transmit data. Because of this fact, the network layer of MANETs is vulnerable to attacks of several kinds. Here in this paper, different kinds of attacks on MANETs are discussed first and then some protection mechanisms against those attacks are discussed. Comparisons of these mechanisms are also included. <s> BIB003
The watch dog technique has been the most well know node misbehavior detection in ad hoc networks. In this technique, every node acts as a watchdog agent monitoring packet transmissions to neighboring nodes BIB002 . The watchdog agents save a copy of packets in their watchdog monitoring buffers before their transmission to the next node. This serves to monitor packet relay from a neighboring node to the next node. . Before 'A' forwards a packet received from 'S', it saves the packet in its watchdog monitoring buffer. After forwarding the packet to 'B', 'A' monitors whether the packet has been forwarded to 'C'. This is because 'A' is expected to receive a copy of the packet forwarded to 'C' since it's within 'B's transmission range. 'A' then compares the received packet with the one saved in its watchdog monitoring buffer. If 'A' fails to receive a copy of the packet from 'B' within certain duration, it reduces the confidence level of 'B' by 0.05. When this happens in recurring manner, the confidence level is set to zero and 'A' decides that 'B' is a malicious node and sends an alarm so as to change the route through 'B'. Meanwhile if 'B' forwards the packet within the time duration, 'A' rewards 'B' by increasing its confidence level by 0.01. Forootaninia et al [10] , proposed an improved version of watch dog technique (I-Watch dog). In IWatch dog technique, the cluster head is assumed to be the watchdog as illustrated in Figure 4 . Figure 4 . Proposed Improved-Watchdog (I-Watchdog) [10] Incase node A wants to communicate with node C, node M which is the cluster head acts as the watchdog. It's assumed that, M has a buffer that accommodates all the sent packets within its range. Node B is the intermediate node between A and C. M monitors the packet forwarding character of B after receiving A's message which is stored in its buffer and compares the received copy from B with the buffered message. If the messages are similar, the buffered message is dropped. Otherwise, it is considered that, B has not sent the message or replaced with another. This work though improves the life span and power consumption of sensor nodes, has not addressed the packet dropping detection inefficiencies of watch dog technique. Under circumstances of ambiguous collision problems, False misbehavior, receiver collision problems insufficient transmission power, Cooperated misbehavior and partial packet dropping BIB001 [27], watch dog technique fails. Since watch dog relies on confidence values, a malicious node can partially drop packets so that its confidence value does not come to zero. This technique is only suitable in environments in which the watch dog agent has knowledge of its two hop neighbors BIB003 . As a result, it is only more effective in source routing protocols like Dynamic Source Routing (DSR).