How to Calculate Network Auditing in NS2

To calculate the Network Auditing in NS2, we have to record and evaluate the network behaviors to make certain that the network performs in terms of specified policies, rules or predicted activities. It focuses on gathering detailed logs of events like packet transmissions, receptions, drops and policy violations and then evaluating these logs to confirm for problems like illegal access, performance bottlenecks and compliance with security protocols.

To calculate and perform network auditing in NS2, follow the given series of steps:

Steps to Calculate Network Auditing in NS2:

  1. Set Up the NS2 Simulation

First, design a network simulation that logs the essential events (transmissions, receptions, drops and so on) in a trace file. This trace file will behave like the audit log, which will later be assessed.

Example NS2 Script for Network Auditing

# Create NS2 simulator instance

set ns [new Simulator]

# Open trace file to record network events

set tracefile [open audit_trace.tr w]

$ns trace-all $tracefile

# Define network nodes

set n0 [$ns node]  ;# Client node

set n1 [$ns node]  ;# Intermediate node

set n2 [$ns node]  ;# Server node

# Create duplex links between nodes

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

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

# Set up UDP traffic from n0 to n2 via n1

set udp0 [new Agent/UDP]

$ns attach-agent $n0 $udp0

set null0 [new Agent/Null]

$ns attach-agent $n2 $null0

$ns connect $udp0 $null0

set cbr0 [new Application/Traffic/CBR]

$cbr0 set packetSize_ 500

$cbr0 set interval_ 0.01

$cbr0 attach-agent $udp0

# Start and stop traffic

$ns at 0.5 “$cbr0 start”

$ns at 4.5 “$cbr0 stop”

# End simulation

$ns at 5.0 “finish”

proc finish {} {

global ns tracefile

$ns flush-trace

close $tracefile

exit 0

}

# Run the simulation

$ns run

Explanation:

  • Trace File: The trace file (audit_trace.tr) captures all network events for auditing purposes.
  • Traffic: UDP traffic is configured from n0 (client) to n2 (server) through n1.
  • Simulation Logging: NS2 logs events like packet enqueues, dequeues, receptions, and drops in the trace file, which will be evaluated later for auditing.
  1. Understand the Trace File for Auditing

The trace file has details about events like when packets are transferred, obtained, dropped, or enqueued. Each line in the trace file indicates a network event and offers details like the timestamp, packet size, event type (+, -, r, d), source and destination node IDs, and protocol type.

Example trace file lines:

+ 0.500000 0 1 udp 500 ——- 1 0.0 0.0 1.0

– 0.510000 0 1 udp 500 ——- 1 0.0 0.0 1.0

r 0.515000 1 2 udp 500 ——- 1 0.0 0.0 1.0

d 0.520000 1 2 udp 500 ——- 1 0.0 0.0 1.0

  • +: Packet enqueued at a node for transmission.
  • –: Packet dequeued for transmission.
  • r: Packet received at a node.
  • d: Packet dropped.
  1. Auditing Metrics

Implement the network auditing by assessing the trace file for the given key metrics and violations:

  • Packet drops: Audit whether packets were dropped because of network congestion, policy violations, or other reasons.
  • Throughput: Compute how much traffic was efficiently transmitted to verify if the network is satisfying its predictable performance goals.
  • Unauthorized access: Identify if any unauthorized nodes are trying to send or obtain traffic.
  • Traffic violations: Validate if any traffic is violating defined network rules (like bandwidth restrictions or access control rules).
  1. Calculate Key Auditing Metrics

Packet Drop Auditing

You can audit whether there are issues like congestion or incorrect routing by verifying for packet drops in the network.

Here’s an AWK script to estimate packet drops:

awk ‘

{

if ($1 == “d”) {  # Detect packet drops

dropped_packets++;

}

}

END { print “Total Dropped Packets:”, dropped_packets; }’ audit_trace.tr

This script sums the amount of packets dropped during the simulation, assisting you audit if the network is experiencing excessive packet loss.

Throughput Auditing

Throughput is another vital metric for auditing. You can measure throughput to make sure that the network is operating as expected.

Here’s an AWK script to calculate throughput:

awk ‘

{

if ($1 == “r” && $3 == “2”) {  # Packet received at node 2 (server)

total_bytes += $6;          # Sum the size of the received packets

}

}

END {

print “Throughput:”, total_bytes / 5.0, “bytes/sec”;  # Divide by simulation time (5 seconds)

}’ audit_trace.tr

This script computes the throughput for node n2 by counting the size of all packets acquired by the server.

Unauthorized Access Detection

Audit the unauthorized access by authenticating if traffic is originating from nodes that are not supposed to send or receive traffic.

Here’s an AWK script to identify traffic from unauthorized nodes:

awk ‘

{

if ($1 == “+” && $3 != “0” && $3 != “1”) {  # Check for unauthorized traffic from nodes other than n0 or n1

unauthorized_packets++;

}

}

END { print “Unauthorized Access Attempts Detected:”, unauthorized_packets; }’ audit_trace.tr

This script certifies if any traffic originates from nodes other than the legal nodes (n0 and n1). If so, it logs it as illegtimate access.

Traffic Violations

You may have particular protocols for your network includes restricting the bandwidth for specific kinds of traffic or preventing access to certain nodes. You can audit for violations of these policies by evaluating the trace file.

For instance, if you have a bandwidth limit for a precise node, you can check if the traffic surpasses that maximum.

Here’s an AWK script to detect bandwidth violations:

awk ‘

{

if ($1 == “+” && $3 == “0”) {  # Check traffic from node 0

total_bytes += $6;          # Sum the size of the transmitted packets

}

}

END {

max_allowed = 1000000;  # Example bandwidth limit in bytes

if (total_bytes > max_allowed) {

print “Bandwidth Violation: Node 0 exceeded allowed bandwidth”;

} else {

print “No Bandwidth Violations Detected”;

}

}’ audit_trace.tr

This script measures the total traffic from node n0 and checks if it surpasses a specified bandwidth limit (e.g., 1 MB).

  1. Custom Network Auditing

You can detect any particular activities or policies in your network by extending the auditing process. For instance, you can audit:

  • Protocol compliance: Make certain that only permitted protocols (like TCP, UDP) are used by authorized nodes.
  • QoS compliance: Ensure that quality of service (QoS) policies are adhered to, such as preferring particular kinds of traffic.
  • Access control auditing: Ensure that specific nodes are only able to access certain resources (like node n0 should only interact with node n1, and not with node n2).
  1. Visualize Audit Data

You can use tools like Python (matplotlib) or Excel to visualize the audit data (like packet drops, throughput, unauthorized access).

Example Python Plot for Packet Drops Over Time:

import matplotlib.pyplot as plt

# Example data for packet drops over time

time = [0.5, 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5]

packet_drops = [0, 5, 10, 15, 20, 25, 30, 35, 40]  # Example packet drop data

plt.plot(time, packet_drops, marker=’o’)

plt.title(‘Packet Drops Over Time’)

plt.xlabel(‘Time (seconds)’)

plt.ylabel(‘Packet Drops’)

plt.grid(True)

plt.show()

Summary

To operate network auditing in NS2:

  1. Set up the simulation: Trace-all command is used to log network events in a trace file.
  2. Analyze the trace file: Use AWK scripts to measure metrics like packet drops, throughput, and unauthorized access.
  3. Detect policy violations: Audit for traffic violations like bandwidth overuse or illegal access.
  4. Custom auditing: Extend the auditing process to verify for certain network policies, QoS compliance, or access control rules.
  5. Visualize results: Use tools like Python or Excel to plot audit data and evaluate the network’s compliance and performance.

At the end of this process, we can now completely aware of how the network auditing is accomplished and calculated in the ns2 simulation and how it performs in the set up. If needed, we can provide you the additional information related to this topic.

Let our experts handle it for you to achieve the best results. Just send us your parameter details, and we will compare them to deliver optimal outcomes. We assist you in calculating Network Auditing using the NS2 tool, tailored to your project ideas and topics that we share.