How to Implement Passive Attacks in NS2

To implement the passive attacks within NS2 (Network Simulator 2), we require to simulate a scenario in which a malicious node within the network listens to the communication of the other nodes without dynamically changing the data. This attacks such as eavesdropping or traffic analyse can be modelled in the simulation tool NS2 by operating the existing network setup. Given below is a simple steps of how to mimic passive attacks in NS2:

Steps to Implement Passive Attack:

  1. Set up the Network Topology:
  • Make the network topology with several nodes using the Tcl (Tool Command Language) scripts.
  • Describe the connections and communication paths among the nodes.
  1. Identify the Malicious Node:
  • Select a node in the network to perform as the malicious node that will inactively monitor traffic.
  • It should only listen to the ongoing communication without transferring or changing the packets.
  1. Modify the Agent for Passive Attack:
  • It do not change or drop packets, thus the malicious node will only capture packets.
  • To replicate this, we can use a null agent on the malicious node to make sure that the node does not involve in any communication however still logs the traffic it receives.
  1. Logging the Traffic (Packet Capture):
  • Alter the malicious node’s performance by logging or logging all received packets.
  • In the simulation NS2, it can be done by appending a method which the logs packets to a file when the malicious node receives a packet.
  • We can use the built-in trace functionality in NS2 to take packet flow for examine.
  1. Simulation Script Example:

The following is a basic Tcl script for configure a passive attack scenario in NS2:

# Define a simulator object

set ns [new Simulator]

# Open the NS trace file

set tracefile [open out.tr w]

$ns trace-all $tracefile

# Define a topology (4 nodes for example)

set n0 [$ns node]

set n1 [$ns node]

set n2 [$ns node]

set n3 [$ns node]

# Create links between nodes

$ns duplex-link $n0 $n1 1Mb 10ms DropTail

$ns duplex-link $n1 $n2 1Mb 10ms DropTail

$ns duplex-link $n2 $n3 1Mb 10ms DropTail

# Set up TCP communication between n0 and n3

set tcp0 [new Agent/TCP]

$ns attach-agent $n0 $tcp0

set sink0 [new Agent/TCPSink]

$ns attach-agent $n3 $sink0

$ns connect $tcp0 $sink0

# Create a traffic source

set ftp0 [new Application/FTP]

$ftp0 attach-agent $tcp0

$ns at 0.1 “$ftp0 start”

# Designate n2 as the passive attacker node (only listens)

set nullAgent [new Agent/Null]

$ns attach-agent $n2 $nullAgent

# Procedure to log all traffic at node n2

$ns at 0.5 “puts \”n2 receiving packets\””

$ns at 1.0 “puts \”Passive attack at n2. Monitoring ongoing traffic…\””

# Schedule simulation end

$ns at 5.0 “finish”

proc finish {} {

global ns tracefile

$ns flush-trace

close $tracefile

exit 0

}

# Run the simulation

$ns run

  1. Analysis of Captured Data:
  • Test the trace file out.tr, after running the simulation. Observe for the packets received by the malicious node (n2 in the instance) to monitor whatever data it is inactively listening to.
  1. Extend the Implementation:
  • We can expand this by executing more furthered traffic analysis and logging the packet headers, or mimicking encryption to detect how a passive attacker can obtain the metadata.
  1. Visualization (Optional):
  • We can use the tools such as NAM (Network Animator) to envision the packet flow and verify that the malicious node is only receiving packets without changing them.

Within the module, we executed a step-by-step approach that to replicate the scenario and implement the Passive Attacks through the simulator NS2. Additional informations with specific details on this topic will be provided as well, if required.

Passive Attacks in NS2 tool implementation are aided by us, if you are in need of help for best research guidance then you can contact us for best support.