How to Implement Network Penetration Testing in NS2

To implement the Network Penetration Testing in Network Simulator 2 (NS2), we have to examine the security of network protocols and set ups by simulating the network’s weakness and attacks. This helps analyse to know how well the network endures different penetration inspecting situations like sniffing, DoS (Denial of Service) attacks or man-in-the-middle attacks. In the following below, we provided the implementation steps on how to test it in ns2:

Step-by-Step Guide to Implement Network Penetration Testing in NS2:

  1. Set Up the Network Topology:
  • Start by configuring the network of nodes that indicates your target network. The nodes uses wired or wireless connections to interact with one another and you will mimic normal traffic as well as capable attacks.
  • For simplicity, we’ll begin with a simplified topology where numerous nodes are communicating, and one node simulates the attacker.

Example OTcl script for a basic network topology:

set ns [new Simulator]

set nf [open out.tr w]

$ns trace-all $nf

set namfile [open out.nam w]

$ns namtrace-all $namfile

# Define nodes

set node0 [$ns node]   ;# Target Node

set node1 [$ns node]   ;# Normal Node

set node2 [$ns node]   ;# Attacker Node

# Create links

$ns duplex-link $node0 $node1 1Mb 10ms DropTail

$ns duplex-link $node0 $node2 1Mb 10ms DropTail

# Set up communication between node0 and node1 (normal traffic)

set udp [new Agent/UDP]

set null [new Agent/Null]

$ns attach-agent $node0 $udp

$ns attach-agent $node1 $null

$ns connect $udp $null

set cbr [new Application/Traffic/CBR]

$cbr attach-agent $udp

$cbr set packetSize_ 512

$cbr set rate_ 1Mb

$ns at 1.0 “$cbr start”

$ns at 5.0 “$cbr stop”

  • This script creates a basic network with three nodes, where node0 and node1 communicate normally, and node2 will be the attacker.
  1. Simulate Normal Traffic:
  • You need to replicate regular traffic on the network before launching attacks. In this case, we are using UDP traffic with the CBR (Constant Bit Rate) application.
  • The communication amongst node0 and node1 represents legitimate traffic, and you will later analyze how this traffic is influenced by attacks.
  1. Implement Attack Simulations (Penetration Testing):
  • You can imitate numerous types of attacks in NS2 to perform penetration testing. Below are some examples of attacks that can be simulated.

Denial of Service (DoS) Attack:

A DoS attack can be simulated by flooding the network with traffic, overwhelming the target node (node0), and guarding against authorized traffic from getting through.

Include the following to your OTcl script to simulate a DoS attack from node2:

# Set up DoS attack traffic from node2 (attacker) to node0 (target)

set udp_attack [new Agent/UDP]

$ns attach-agent $node2 $udp_attack

$ns connect $udp_attack $null

set cbr_attack [new Application/Traffic/CBR]

$cbr_attack attach-agent $udp_attack

$cbr_attack set packetSize_ 512

$cbr_attack set rate_ 5Mb  ;# Higher traffic rate to simulate a flood

# Start the attack at 2.0 seconds

$ns at 2.0 “$cbr_attack start”

$ns at 5.0 “$cbr_attack stop”

  • In this case, the attack begins at 2.0 seconds, delivering a flood of 5Mbps traffic from node2 (attacker) to node0 (target). You can compare how the legitimate traffic from node0 to node1 is affected.

Sniffing Attack (Passive Eavesdropping):

A sniffing attack can be simulated by recording all the packets that pass through node2 (attacker). This simulates an attacker intercepting and capturing network traffic.

Example alteration for packet sniffing at node2:

# Set up sniffing by logging all packets at node2 (attacker)

set nf2 [open sniffed_packets.tr w]

$ns trace-all $nf2 $node2

  • In this case, all packets passing through node2 will be logged to sniffed_packets.tr, replicating a passive sniffing attack.

Man-in-the-Middle (MITM) Attack:

A MITM attack can be simulated by intercepting and fine-tuning the traffic amongst node0 and node1. In this case, node2 will capture packets from node0, alter them, and then dispatch them to node1.

Example OTcl script modification for a MITM attack:

# Define attacker node2 to intercept and alter traffic

proc intercept_and_alter {pkt} {

# Intercept and modify the packet

set hdr [Packet::gethdr $pkt]

set src [$hdr src_]

set dst [$hdr dst_]

if { $src == $node0 && $dst == $node1 } {

# Modify the packet (for example, alter the payload)

set payload [Packet::getdata $pkt]

set new_payload “Modified Data”

Packet::setdata $pkt $new_payload

# Forward the modified packet to the original destination

$node2 send $pkt $node1

}

}

# Bind the interception function to the agent at node2

$ns at 2.0 “attach_sniffer $node2 intercept_and_alter”

  • Here, node2 interrupts packets from node0, adjusts their payload, and then forwards them to node1, simulating a MITM attack.
  1. Run the Simulation and Collect Data:
  • After including the attacks, execute the simulation and produce trace files. You can assess the influence of each attack on network performance and security.
  • Example:

ns your_script.tcl

  1. Analyze the Results:
  • Analyze the effects of attacks on the network by looking at key metrics such as:
    • Packet loss: Compute how much authentic traffic is lost because of the attack.
    • Throughput: Verify how the traffic throughput is impacted by the attack.
    • Packet delay: Estimate the increase in end-to-end delay due to the attack.
    • Traffic analysis: Examine the trace files to see if the attacker successfully intercepted or altered traffic.

Example AWK script to calculate packet loss:

awk ‘

BEGIN { sent_packets = 0; received_packets = 0; }

{

if ($1 == “+” && $4 == “UDP”) sent_packets++;

if ($1 == “r” && $4 == “UDP”) received_packets++;

}

END {

packet_loss = sent_packets – received_packets;

print “Packet Loss:”, packet_loss;

}’ out.tr

  • This script will help you detect how many authorized packets were lost caused by attack.
  1. Visualize the Attack in NAM:
  • NS2 makes a NAM (Network Animator) file (out.nam) that you can use to visualize the network activity during the attack.
  • Execute NAM to monitor how the attacker interacts with the rest of the network:

nam out.nam

  • This will show you the movement of packets across the network, where you can observe how attacks like DoS, sniffing, or MITM affect the network visually.

Summary of Penetration Testing Techniques:

  1. DoS Attack Simulation: Simulate a flooding attack to overwhelm a node, impacting legal traffic.
  2. Sniffing/Eavesdropping Attack: Capture and record network traffic to replicate an attacker listening to all packets.
  3. Man-in-the-Middle Attack: Intercept and adjust packets in transit, mimicking a MITM attack.
  4. Traffic Analysis: Gather and evaluate trace files for key metrics (packet loss, throughput, delay) to understand the influence of the attacks.

In conclusion, we offered the detailed demonstration on how to implement Network Penetration Testing in the NS2 by simulating different attack techniques and observe how network guards respond. We also provide some sample snippets and its strategies in detail. Let us know your requirements, and we will provide you with further assistance. If you need more help with implementing Network Penetration Testing using the NS2 tool, feel free to visit ns2project.com for additional support. We also offer performance analysis services. Our team specializes in scenarios such as sniffing, DoS (Denial of Service) attacks, man-in-the-middle attacks, and more for your projects. Additionally, we can suggest the best project topics.