09-11-2012, 02:24 PM
Grayhole Attack and Prevention in Mobile Adhoc Network
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ABSTRACT
Mobile ad-hoc networks (MANETs) are composed of autonomous
nodes that are self- managed, dynamically deployed without any
pre-existing infrastructure. Gray hole attacks are an active type of
attack, which leads to dropping of messages, attacking node first
agrees to forward packets and then fails to do so. For this we are
using an AODV routing protocol to discover route. Initially the
Malicious node behaves correctly and a reply sends true Route
Reply (RREP) messages to nodes that initiate Route request
(RREQ) messages. We use an intrusion detection system (IDS) to
monitors the network or system activities for malicious activities
or policy violation and produces reports to a Management Station.
It takes over the sending packets. Afterwards, the node just drops
the packets to launch a (DoS) denial of service attack. If neighbors
nodes that try to send packets over attacking nodes lose the
connection to destination then they may want to discover a route
again and broadcasting Route Request (RREQ) messages. In
Network Simulation-2 (NS-2) scenario the simulation result has
shown that the throughput packet delivery is improved rather than
traditional Gray hole attack.
INTRODUCTION
MANETs [1] are composed of autonomous nodes that are selfmanaged
without any infrastructure. In this way, ad-hoc net works
have a dynamic topology such that nodes can easily join or leave
the network at any time. MANETs are suitable for areas where it is
not possible to set up a fixed infrastructure. Since the nodes
communicate with each other without an infrastructure, they
provide the connectivity by forwarding packets over themselves.
To support this connectivity, nodes use some routing protocols [2]
[3] such as AODV (Ad-hoc On-Demand Distance Vector), DSR
(Dynamic Source Routing) and DSDV (Destination-Sequenced
Distance-Vector). Each node also acts as a router to discover a path
and forward packets to the correct node in the network. As
MANETs lack an infrastructure, they are exposed to a lot of
attacks. One of these attacks is the Gray Hole attack. In the Gray
Hole attack [4], which lead to dropping of messages? Attacking
node first agrees to forward packets and then fails to do so. Gray
Hole attack [4] may occur due to a malicious node which is
deliberately misbehaving, as well as a damaged node interface we
simulated the Gray Hole attack node which is deliberately
misbehaving, as well as a damaged node interface we simulated
the Gray Hole attack.
Background theory
Intrusion Detection System aimed to securing the AODV protocol
using our Intrusion Detection system. They conclude that AODV
performs well at all mobility rates and movement speeds.
However, we argue that their definition of mobility (pause time)
does not truly represent the dynamic topology of MANETs. In this
thesis, the work of has been extended and the proposed protocol is
called IDSAODV (Intrusion Detection System AODV). Use of
AODV based intrusion detection. Our Intrusion Detection and
Response Protocol for MANETs have been demonstrated to
perform better than that AODV protocol and presence of Gray
Hole Attack, in terms of false positives and percentage of packets
delivered. Since the earlier work do not report true positive i.e. the
detection rate, we could not compare our results against that
parameter with their method[1]. The implementation of the
IDSAODV protocol reported in this thesis has shown to work in
real life scenarios. IDSAODV performs real time detection of
attacks in MANETs running AODV routing protocol.
Experimental results validate the ability of our protocol to
successfully detect both local and distributed attacks against the
AODV routing protocol, with a low number of false positives. The
algorithm also imposes a very small overhead on the nodes, which
is an important factor for the resource constrained nodes.
4. Proposed methodology
To explain the Gray Hole Attack we added a malicious node that
exh ibits Gray Hole Therefore, we cloned the “AODV” p rotocol,
chan gin g it to “IDSAODV” as we did “Gray hole” before. To
implement the gray hole we changed the receive RREP function of
the grayholeaodv.cc file but to implement the solution we had to
change the receive RREP and create RREP caching mechanism to
count the second RREP message.
CONCLUSION
Every protocol being simulated using the same parameters that had
been discussed to ensure the simulation produced accurate results.
In MANET we can find the performance and QoS of the various
matrices and overcome the destroyed packet and drop rate,
Transmission rate of these three metrics and compare with the
AODV Protocols. The analysis had been done through simulation
using commercial and highly reliable tool like Network Simulator
(NS2).The performances comparison of the four routing protocols
for mobile ad hoc networks.Here we gives summarize result in
normal AODV protocol case, Gray Hole Attack case and IDS case
that time we take parameter total number of packets send, total
number of packets receive by the genuine receiver, routing load
packet delivery ratio, Average end to end delay etc.