How to Simulate Network Forensics in NS2

To implement the Network Forensics in ns2 encompasses to monitor, log, analyze and finding network activities to spot malicious behaviors, aggregate evidence of cyberattacks and make sure data integrity. In ns2, we can detect and lessen the security incidents by simulating various attack scenarios, record network traffic and evaluate records. This process helps to recreate the chain of events during or after an attack.

The below guide show you how to implement Network Forensics in NS2:

Step-by-Step Implementation:

  1. Set Up NS2

Make certain that NS2 is installed on your system. You can install it using the below command:

sudo apt-get install ns2

  1. Define the Network Topology

Begin by stating a basic network topology in NS2 where data is interchanged and malicious activities are replicated for forensic analysis.

Example:

set ns [new Simulator]

set tracefile [open forensics_analysis.tr w]

$ns trace-all $tracefile

# Create nodes

set n1 [$ns node]  ;# Sender node

set n2 [$ns node]  ;# Receiver node

set nAttacker [$ns node]  ;# Attacker node

set nMonitor [$ns node]   ;# Monitoring node (forensic analysis)

# Create links between nodes

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

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

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

  1. Set Up Normal Traffic

Mimic the normal flow of traffic amongst the sender (n1) and receiver (n2). The observing node (nMonitor) will be used to capture traffic for forensic analysis.

# Set up UDP traffic between n1 and n2

set udp1 [new Agent/UDP]

set null1 [new Agent/Null]

$ns attach-agent $n1 $udp1

$ns attach-agent $n2 $null1

$ns connect $udp1 $null1

# Create CBR (Constant Bit Rate) traffic generator attached to UDP

set cbr1 [new Application/Traffic/CBR]

$cbr1 set packetSize_ 512

$cbr1 set rate_ 1Mb

$cbr1 attach-agent $udp1

# Start the normal traffic at 1.0 second

$ns at 1.0 “$cbr1 start”

  1. Simulate Malicious Activity (Attack Scenarios)

You can imitate various attack incidents like packet injection, DDoS, man-in-the-middle attacks, and more. These attacks will be introduced from the attacker node (nAttacker).

(A) Packet Injection Attack Simulation

Packet injection simulates illegitimated packets being inserted into the network by the attacker node.

# Set up packet injection from the attacker node

set udpAttacker [new Agent/UDP]

set cbrAttacker [new Application/Traffic/CBR]

$cbrAttacker set packetSize_ 512

$cbrAttacker set rate_ 5Mb  ;# High rate to simulate attack

$cbrAttacker attach-agent $udpAttacker

# Connect attacker to the receiver node

$ns attach-agent $nAttacker $udpAttacker

$ns connect $udpAttacker $null1

# Start the attack at 2.0 seconds

$ns at 2.0 “$cbrAttacker start”

(B) DDoS Attack Simulation

Replicate a Distributed Denial of Service (DDoS) attack by having the attacker node produce an excessive amount of traffic to overwhelm the receiver.

# Simulate a DDoS attack by generating high-rate traffic

$cbrAttacker set rate_ 10Mb  ;# Very high rate for DDoS

$ns at 2.5 “$cbrAttacker start”

(C) Man-in-the-Middle Attack Simulation

Simulate a man-in-the-middle (MITM) attack where the attacker intercepts and capably changes the communication amongst the sender and receiver.

# Intercept traffic from n1 to n2 (man-in-the-middle attack)

$ns at 3.0 “$ns duplex-link $n1 $nAttacker 1Mb 10ms DropTail”

$ns at 3.5 “$ns connect $udp1 $udpAttacker”  ;# Intercept the traffic

  1. Set Up Traffic Monitoring and Logging

In forensic analysis, observing network traffic is important. The monitoring node (nMonitor) will capture all network activities for analysis as well as normal traffic and attacks.

(A) Log Traffic for Forensic Analysis

You can log all traffic passing through the monitoring node by seizing related packet details (source, destination, packet size, timestamp, etc.).

# Function to log packet details for forensic analysis

proc log_packet {packet_id source dest size time} {

puts “Packet $packet_id: Source=$source, Dest=$dest, Size=$size, Time=$time”

}

# Simulate logging of traffic at the monitor node

proc monitor_traffic {packet_id source dest size time} {

log_packet $packet_id $source $dest $size $time

}

# Capture traffic at monitor node for forensic analysis

$ns at 1.5 “monitor_traffic 1 n1 n2 512 1.5”

$ns at 2.5 “monitor_traffic 2 nAttacker n2 512 2.5”  ;# Log attack traffic

(B) Record Traffic for Replay

Forensics may involve logging traffic for replay and deeper analysis. You can store logs in a file and analyze them after the simulation.

# Open a file to store the traffic log for forensic purposes

set forensic_log [open forensic_log.txt w]

# Log traffic to the file

proc log_traffic_to_file {packet_id source dest size time} {

global forensic_log

puts $forensic_log “Packet $packet_id: Source=$source, Dest=$dest, Size=$size, Time=$time”

}

# Log traffic at the monitor node

$ns at 1.5 “log_traffic_to_file 1 n1 n2 512 1.5”

$ns at 2.5 “log_traffic_to_file 2 nAttacker n2 512 2.5”

  1. Simulate Forensic Investigation (Post-Event Analysis)

In network forensics, you need to assess logs for suspicious patterns, replay recorded traffic, and trace the attacker’s actions. It can be applied by using manual inspection of the logs or by using an automated detection system.

(A) Forensic Evidence Extraction

Once traffic has been logged, you can extract related forensic evidence like packet traces, timestamps, and potential attack patterns (for instance: abnormally high traffic from a specific node).

Example:

# Forensic analysis function

proc analyze_traffic_log {file} {

puts “Analyzing traffic log for anomalies…”

set logfile [open $file r]

while {[gets $logfile line] >= 0} {

if {[regexp {nAttacker} $line]} {

puts “Potential attack detected: $line”

}

}

close $logfile

}

# Perform forensic analysis of the log after the simulation

$ns at 5.0 “analyze_traffic_log forensic_log.txt”

(B) Traffic Replay for Forensic Analysis

Replay captured traffic in a controlled environment to inspect the impacts of the attack and accumulate evidence.

# Replay traffic for forensic analysis

proc replay_traffic {packet_id source dest size time} {

puts “Replaying packet $packet_id from $source to $dest with size $size at $time”

# Simulate replay of captured traffic here

}

$ns at 5.5 “replay_traffic 1 n1 n2 512 1.5”

  1. Implement Mitigation Techniques

We can execute mitigation strategies include blocking the attacker or redirecting traffic away from compromised nodes depends on the forensic analysis.

Example: Blocking Malicious Traffic

# Function to block traffic from the attacker node

proc block_attacker {node} {

puts “Blocking traffic from $node”

$ns detach-agent $node

}

# Block the attacker if malicious activity is detected

$ns at 3.0 “block_attacker nAttacker”

  1. Run the Simulation

Once the script is ready, execute the simulation using NS2:

ns your_script.tcl

  1. Analyze Results

After the simulation is done, evaluate the forensic logs (forensic_log.txt) to detect patterns of malicious activity like:

  • Abnormal traffic patterns: High traffic from particular nodes representing DDoS attacks.
  • Unauthorized packets: Packets from untrusted sources (such as packet injection attacks).
  • Timestamp discrepancies: denoting capable replay attacks.

You can also use NAM (Network Animator) to envision the network activity and investigate how the attacks affected the network.

  1. Extend the Simulation

You can extend this implementation by:

  • Adding more attack types: Replicate various types of attacks like spoofing, eavesdropping, or malware injection.
  • Using encryption: Imitate encrypted traffic to make attacks harder to spot and estimate how decryption keys or certificates could be involved in forensic investigations.
  • Using real-time detection systems: Incorporate intrusion detection or prevention systems (IDS/IPS) for realistic attack detection and mitigation.
  • Improving forensic accuracy: Include latest mechanisms like packet tagging, timestamping, and hashing to cerify packet integrity and trace packet sources.

With this approach, we can configure the simple network forensics simulation in ns2 that focuses on discovering the network traffic and assessing it for forensic purposes. You can identify and capture the malevolent activities in the network by following the provided demonstration process. To implement the Network Forensics in ns2 you can share all your research details to us we offer   best research ideas .