How to Begin Implement a Virtual Private Network Projects in NS3

To begin executing a Virtual Private Network (VPN) project in NS3, it requires replicating the secure and encrypted interaction among the nodes through public or private network. VPNs make sure that data confidentiality, integrity, and secure access to resources for creating them which is crucial in advanced networking.

Below is a stepwise procedure on how we can approach it:

Steps to Begin Implementing a Virtual Private Network Projects in NS3

1. Understand VPN Concepts

• Key Features:
  • Encryption: To protect the data within transit.
  • Tunneling: Packets encapsulation for secure data transmission.
  • Authentication: Before permitting access to confirm user identity.
• Common Protocols:
  • IPsec (Internet Protocol Security): It offers encryption and authentication.
  • SSL/TLS (Secure Socket Layer/Transport Layer Security): It is utilized within HTTPS-based VPNs.
  • OpenVPN/WireGuard: Modern and lightweight VPN protocols.

2. Set Up NS3 Environment

• Initially, we should install and download the new version of NS3 on the system.
• Make sure that we have installed all required dependencies with OpenSSL as adding encryption libraries.
• Learn about NS3 modules such as PointToPoint, Applications, Internet, and TrafficControl.

3. Define Project Objectives

• Decide on the VPN type for replicating:
  • Site-to-Site VPN: It securely associates two or multiple networks.
  • Remote Access VPN: Offers secure access for remote users.
  • Overlay VPN: It is used for multi-site organizations through the internet.
• Select the protocol and encryption mechanism for usage.

4. Design the VPN Topology

• VPN Gateways: Denote the routers or firewalls to handle the VPN tunnels.
• Client Nodes: Replicate users are getting into VPN.
• Secure Tunnels: Mimic encryption and encapsulation through the public network.

5. Basic VPN Simulation Structure

• Nodes: Signify clients, gateways, and servers.
• Links: Public network including potential packet loss and latency.
• Traffic: Encrypted traffic that generated by clients and servers.

6. Example Simulation

Below is a sample script to replicate a VPN including secure communication:

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/internet-module.h”

#include “ns3/point-to-point-module.h”

#include “ns3/applications-module.h”

using namespace ns3;

int main(int argc, char *argv[]) {

CommandLine cmd;

cmd.Parse(argc, argv);

// Create nodes

NodeContainer clientNodes, serverNode, vpnGateways;

clientNodes.Create(2); // Two clients

serverNode.Create(1);  // One server

vpnGateways.Create(2); // Two VPN gateways

// Create public network links

PointToPointHelper p2p;

p2p.SetDeviceAttribute(“DataRate”, StringValue(“10Mbps”));

p2p.SetChannelAttribute(“Delay”, StringValue(“5ms”));

NetDeviceContainer publicDevices;

publicDevices.Add(p2p.Install(vpnGateways.Get(0), vpnGateways.Get(1))); // VPN gateway link

// Connect clients to VPN gateway 1

NetDeviceContainer clientDevices;

for (uint32_t i = 0; i < clientNodes.GetN(); ++i) {

clientDevices.Add(p2p.Install(clientNodes.Get(i), vpnGateways.Get(0)));

}

// Connect VPN gateway 2 to server

NetDeviceContainer serverDevices;

serverDevices.Add(p2p.Install(vpnGateways.Get(1), serverNode.Get(0)));

// Install Internet stack

InternetStackHelper stack;

stack.Install(clientNodes);

stack.Install(serverNode);

stack.Install(vpnGateways);

// Assign IP addresses

Ipv4AddressHelper ipv4;

ipv4.SetBase(“10.1.1.0”, “255.255.255.0”);

ipv4.Assign(clientDevices);

ipv4.SetBase(“10.1.2.0”, “255.255.255.0”);

ipv4.Assign(publicDevices);

ipv4.SetBase(“10.1.3.0”, “255.255.255.0”);

ipv4.Assign(serverDevices);

// Simulate encrypted communication (e.g., HTTPS or IPsec-like behavior)

uint16_t port = 443; // HTTPS port

OnOffHelper onOff(“ns3::TcpSocketFactory”, Address(InetSocketAddress(Ipv4Address(“10.1.3.1”), port)));

onOff.SetAttribute(“DataRate”, StringValue(“1Mbps”));

onOff.SetAttribute(“PacketSize”, UintegerValue(1024));

onOff.SetAttribute(“StartTime”, TimeValue(Seconds(1.0)));

ApplicationContainer clientApps = onOff.Install(clientNodes.Get(0));

clientApps.Start(Seconds(2.0));

clientApps.Stop(Seconds(10.0));

PacketSinkHelper sink(“ns3::TcpSocketFactory”, Address(InetSocketAddress(Ipv4Address::GetAny(), port)));

ApplicationContainer serverApps = sink.Install(serverNode.Get(0));

serverApps.Start(Seconds(1.0));

serverApps.Stop(Seconds(10.0));

Simulator::Run();

Simulator::Destroy();

return 0;

}

7. Enhance the Simulation

• Encryption and Authentication:
  • Add OpenSSL for encryption simulation.
  • Replicate the IPsec-like ESP (Encapsulation Security Payload) packets.
• Tunnel Simulation:
  • Mimic tunneled traffic among the gateways to utilize IP encapsulation.
• Traffic Models:
  • Make various traffic models like video streaming, file transfers.
• Multi-Site VPN:
  • Integrate additional gateways and then replicate a multi-site VPN network.

8. Performance Metrics

• Latency: Assess delays that are launched by encryption and tunneling.
• Throughput: Measure the rate of data which are transmitted by VPN.
• Packet Loss: Examine reliability with encryption overhead.
• Overhead: Evaluate more necessary bandwidth for encryption and tunneling.

9. Advanced Features

• Dynamic VPN Configuration:
  • Actively replicate route and tunnel set up.
• SDN-Driven VPN:
  • Add an SDN controller for VPN management.
• Hybrid VPN:
  • In a single topology, we can integrate the site-to-site and remote-access VPNs.

10. Visualization and Analysis

• For envisioning the network traffic, we should utilize NetAnim tools.
• Examine the simulation records to leverage external tools such as Python or MATLAB for in-depth insights.

11. Extensions

• QoS in VPN:
  • Execute the Quality of Service to give precedence particular kinds of traffic.
• Security Testing:
  • Mimic attacks such as packet sniffing, man-in-the-middle and experiment the resilience of VPN.
• Energy Efficiency:
  • Examine the energy utilization within VPN-enabled devices.

In this approach, you can thoroughly focus and learn the concept behind the implementation of the Virtual Private Network that were executed and simulated in the NS3 environment. We will deliver detailed steps through another manual.