How to Start Virtual Private Networks Projects Using NS2

To start a Virtual Private Network (VPN) project in NS2 (Network Simulator 2), we will need to replicate the network scenarios that contains encryption, tunnelling, and secure interaction in the network, we follow these steps to get started:

Steps to Start Virtual Private Network Projects in NS2

  1. Understand the Basics of VPNs in NS2
  • What is a VPN?
    • A Virtual Private Network (VPN) allows secure interaction through the public or shared networks with the support of encryption and tunneling protocols.
  • Key Components for VPN Simulation:
    • Nodes: It denotes routers, servers, and clients.
    • Encryption: Replicate the data security like DES, AES.
    • Tunneling: Capture data packets to utilise protocols such as GRE or IPsec.
    • Traffic: Replicate the real-time traffic with TCP/UDP.
  1. Install and Set Up NS2
  • Install NS2 using:

sudo apt-get update

sudo apt-get install ns2

  • Confirm installation by executing:

ns

If % occurs then installation is effectively functioned.

  1. Define Your VPN Project Goals
  • Replicate the secure interaction among two or more locations.
  • Execute encryption and tunneling protocols.
  • Estimate the performance parameters such as latency, packet loss, encryption overhead.
  1. Plan the VPN Network Topology
  • Create a network topology in which:
    • A public network as the internet which includes private subnets or nodes.
    • VPN tunnels are launched among the routers or gateways.
  1. Create a Basic VPN Simulation

Here’s a Tcl script to replicate a VPN-like scenario:

Example VPN Simulation Script

# Create a Simulator Object

set ns [new Simulator]

# Trace Files for Output

set tracefile [open vpn.tr w]

$ns trace-all $tracefile

set namfile [open vpn.nam w]

$ns namtrace-all $namfile

# Define Network Nodes

set client [$ns node]

set vpn_gateway1 [$ns node]

set public_router [$ns node]

set vpn_gateway2 [$ns node]

set server [$ns node]

# Create Links

$ns duplex-link $client $vpn_gateway1 10Mb 10ms DropTail

$ns duplex-link $vpn_gateway1 $public_router 5Mb 50ms DropTail

$ns duplex-link $public_router $vpn_gateway2 5Mb 50ms DropTail

$ns duplex-link $vpn_gateway2 $server 10Mb 10ms DropTail

# Simulate Encryption Overhead (by adjusting delay and throughput)

$ns queue-limit $vpn_gateway1 $public_router 50

$ns queue-limit $public_router $vpn_gateway2 50

# Configure VPN Tunneling (Encapsulation)

# This is a simulated tunneling effect with added latency

$ns queue-limit $vpn_gateway1 $vpn_gateway2 100

# Attach Traffic Agents

set tcp [new Agent/TCP]

set sink [new Agent/TCPSink]

$ns attach-agent $client $tcp

$ns attach-agent $server $sink

$ns connect $tcp $sink

# Traffic Generator

set ftp [new Application/FTP]

$ftp attach-agent $tcp

$ftp start

# Simulation End Procedure

proc finish {} {

global ns tracefile namfile

$ns flush-trace

close $tracefile

close $namfile

exec nam vpn.nam &

exit 0

}

$ns at 10.0 “finish”

# Run Simulation

$ns run

  1. Add Encryption to Simulate VPN Security

NS2 doesn’t have native support for encryption thus we need to replicate it:

  • Simulating Encryption Overhead: Integrate the artificial delays or minimize throughput for replicating encrypted packets.
  • Custom Modules: Inscribe or incorporate the custom components of encryption mechanisms within C++ for NS2.
  1. Analyze VPN Performance
  • Metrics to Analyze:
    • Encryption Overhead
    • Throughput
    • Latency
    • Packet Loss
  • Trace File Analysis: Analyse the performance parameters from the trace file (vpn.tr) to utilise AWK or Python scripts.
  • Visualize with NAM: Go to the NAM file to envision the outcomes:

nam vpn.nam

  1. Enhance the VPN Simulation
  • Advanced Topologies: It has numerous VPN tunnels which are associating various subnets.
  • Real-World Traffic: Mimic real-time traffic pattern to utilise HTTP, FTP, VoIP, or video streaming traffic.
  • Dynamic Routing: Launch the dynamic routing protocols such as OSPF or BGP for replicating WAN and inter-site interaction.
  1. Experiment with VPN Scenarios
  • Encryption Protocols: Replicate the effect of various encryption mechanisms like DES, AES.
  • Tunneling Protocols: We will need to estimate the performance to utilise tunnelling approaches such as GRE or IPsec-like sets up.
  • Congestion Control: Focus on how VPN traffic affects the network congestion.
  1. Document Results
  • Simulation Report:
    • It offers comprehensive details that contains objective of the project.
    • Network topology and protocol specifics.
    • Performance parameters and observations.
  • Graphs and Charts: For visual representation, we can utilise the Gnuplot or MATLAB tools to envision the outcomes.

We provided detailed and step-by-step simulation instructions for Virtual Private Networks projects using NS2 environment with additional details like specific configurations or custom module development for VPN project in NS2 to be featured in the upcoming manual.