How to Implement DDoS Attack in NS2

To implement the Distributed Denial of Service (DDoS) attack in Network Simulator 2 (NS2), we have to simulate an environment in which the malevolent nodes (attackers) will flood a target node with irresistible number of traffic. So, it will exhaust the resources of the target, leading to ignorance for authorized users. The below demonstration will help you implement the DDoS attack in ns2:

Key Steps to Implement a DDoS Attack in NS2:

  1. Setting up the network topology: Generate a network with legal nodes and several attacker nodes that deliver a large volume of traffic to the victim node.
  2. Simulating normal traffic: Accomplish legitimate communication amongst nodes.
  3. Simulating malicious traffic: Produce traffic toward the victim node in an effort to overwhelm its resources by configuring numerous nodes.

Example TCL Script to Simulate a DDoS Attack in NS2

Follow the below example of how to implement a DDoS attack in NS2:

  1. Setting Up the Network Topology

In this instance, we generate several mischievous nodes (attackers) and a target node. The attackers will send UDP traffic at a high rate to devastate the target node.

# Create a new simulator instance

set ns [new Simulator]

# Open trace and nam files

set tracefile [open “ddos_attack_trace.tr” w]

$ns trace-all $tracefile

set namfile [open “ddos_attack.nam” w]

$ns namtrace-all-wireless $namfile

# Define network nodes (victim and legitimate users)

set victim [$ns node]  ;# Target of the DDoS attack

set legit_src [$ns node]  ;# Legitimate user node

# Define attacker nodes (multiple nodes performing the DDoS attack)

set attacker1 [$ns node]

set attacker2 [$ns node]

set attacker3 [$ns node]

set attacker4 [$ns node]

# Create a UDP connection for legitimate traffic

set udp_legit [new Agent/UDP]

set null_legit [new Agent/Null]

$ns attach-agent $legit_src $udp_legit

$ns attach-agent $victim $null_legit

$ns connect $udp_legit $null_legit

# Create a CBR application to simulate legitimate traffic

set cbr_legit [new Application/Traffic/CBR]

$cbr_legit set packetSize_ 512

$cbr_legit set rate_ 128Kb

$cbr_legit attach-agent $udp_legit

# Procedure to simulate the DDoS attack (high-rate UDP flooding)

proc ddos_attack {attacker victim} {

global ns

# Create UDP agents for the attacker

set udp_attacker [new Agent/UDP]

set null_attacker [new Agent/Null]

$ns attach-agent $attacker $udp_attacker

$ns attach-agent $victim $null_attacker

$ns connect $udp_attacker $null_attacker

# Create a CBR application for the attacker

set cbr_attack [new Application/Traffic/CBR]

$cbr_attack set packetSize_ 512

$cbr_attack set rate_ 10Mb  ;# High traffic rate to flood the victim

$cbr_attack attach-agent $udp_attacker

# Start sending attack traffic

$ns at 1.0 “$cbr_attack start”

$ns at 5.0 “$cbr_attack stop”

}

# Start legitimate traffic

$ns at 0.5 “$cbr_legit start”

$ns at 5.0 “$cbr_legit stop”

# Start DDoS attack from multiple attacker nodes

$ns at 1.0 “ddos_attack $attacker1 $victim”

$ns at 1.0 “ddos_attack $attacker2 $victim”

$ns at 1.0 “ddos_attack $attacker3 $victim”

$ns at 1.0 “ddos_attack $attacker4 $victim”

# Define finish procedure

proc finish {} {

global ns tracefile namfile

$ns flush-trace

close $tracefile

close $namfile

exec nam ddos_attack.nam &

exit 0

}

# End the simulation at 6.0 seconds

$ns at 6.0 “finish”

# Run the simulation

$ns run

Explanation of the Script:

  1. Network Setup:
    • There are few nodes: one victim node (the target of the DDoS attack), one legitimate node, and several attacker nodes (4 in this example).
    • Authorized traffic is sent from the legal node to the victim, and the attacker nodes flood the victim with traffic to replicate a DDoS attack.
  2. Legitimate Traffic:
    • Valid traffic is modeled using UDP and a CBR (Constant Bit Rate) traffic generator.
    • The legitimate traffic has a moderate data rate (128 Kbps), imitating normal user traffic.
  3. DDoS Attack:
    • Each attacker node delivers high-rate UDP traffic (10 Mbps) toward the victim.
    • The ddos_attack procedure configures a UDP agent on each attacker node, links it to the victim, and uses a CBR traffic generator to flood the victim node with traffic.
    • All attacker nodes start sending traffic at time 1.0 second and end at time 5.0 seconds.
  4. Trace Files and Visualization:
    • The simulation is stored in a trace file (ddos_attack_trace.tr), and NAM can be used to visualize the DDoS attack using the NAM file (ddos_attack.nam).
  1. Customizing the DDoS Attack

You can optimize the DDoS simulation by attaching more mechanisms or tailoring various characteristics of the attack:

  1. a) Increasing the Number of Attackers:

Generate a larger DDoS attack by increasing the count of attacker nodes. Simply include more attacker nodes and alter the script accordingly:

set attacker5 [$ns node]

$ns at 1.0 “ddos_attack $attacker5 $victim”

  1. b) Varying the Traffic Rates:

You can change the traffic rates of the attackers to replicate various kinds of DDoS attacks (such as low-rate attacks or high-volume attacks). You can vary the rate in the ddos_attack procedure:

$cbr_attack set rate_ 5Mb  ;# Adjust the traffic rate

  1. c) Using TCP Traffic for the Attack:

You can alter the DDoS attack to utilize TCP rather than UDP. This would replicate several variant of attack includes TCP SYN flood.

Swap the UDP agent with a TCP agent:

set tcp_attacker [new Agent/TCP]

set sink [new Agent/TCPSink]

$ns attach-agent $attacker $tcp_attacker

$ns attach-agent $victim $sink

$ns connect $tcp_attacker $sink

  1. d) Monitoring and Logging the Attack:

Evaluate the influence of the DDoS attack by logging the counts of packet or victim node’s obtained bytes. You can also track packet drops because of jamming.

Example for logging packet information:

proc log_traffic {node} {

global ns

set pkts_received [$node set recv_]

puts “Victim node $node received $pkts_received packets”

}

$ns at 5.5 “log_traffic $victim”

  1. Analyzing the DDoS Attack

After running the simulation, monitor the effect of the DDoS attack on the victim by examining the trace file. You can write parsing scripts in Python, AWK, or Perl to extract useful statistics includes:

  • Packets received by the victim.
  • Packet drop rate due to blockage.
  • Bandwidth usage during the attack.

Envision how the attack influences the victim node and see the traffic flow from the attackers to the victim by using NAM.

  1. Advanced DDoS Simulation Scenarios

You have to integrate the given mechanisms to generate a more advanced DDoS simulations:

  1. a) Attack Detection and Mitigation:

You can simulate detection mechanisms that detect the DDoS attack and mitigate it by hindering particular attacker nodes or throttling their traffic.

  1. b) Botnet Simulation:

You can replicate a botnet-style DDoS attack where attacker nodes are allocated over the network and controlled by a central command node.

  1. c) Realistic Traffic Patterns:

You can use various traffic patterns (like Poisson distribution or bursty traffic) to replicate more realistic attack and authorized traffic scenarios.

In this set up, you can obtain the knowledge regarding how to set up the network topology and how to customize the DDoS attack simply by modifying the number of traffic and how to enhance this simulation for future enhancement of Distributed Denial of Service (DDoS) attack in ns2. Reach out to ns2project.com for expert advice on effectively implementing DDoS attack simulations in NS2.