How to Begin Implement VLAN Trunking Protocol in NS3

To implement VLAN Trunking Protocol (VTP) using NS3 which is a Cisco-proprietary protocol that frequently utilized for handling the VLAN sets up through a network of switches. To execute VTP within NS3 that has contains to replicate the VLANs, sustain a consistent VLAN database through simulated switches, and actively modernizing VLAN sets up.

Below is a step-by-step approach on how to implement the VLAN Trunking Protocol (VTP) in NS3:

Steps to Begin Implement VLAN Trunking Protocol in NS3

Step 1: Understand VLAN Trunking Protocol (VTP)

1. Key Concepts:
   • VTP Modes:
     • Server Mode: Switches in this mode can make, change, and remove the VLANs. These updates are broadcasted to every switch.
     • Client Mode: Within this mode, switches inherit the updates of VLAN from servers however it cannot create modifications.
     • Transparent Mode: Switches do not take part in VTP nevertheless it transmits the VTP advertisements.
   • VTP Advertisement:
     • VLAN updates are forwarded as commercials, making sure reliability through the network.
   • VLAN Database:
     • A table saving the VLAN database IDs and its names.
2. Use Cases:
   • It sustains consistent VLAN sets up including numerous switches within networks.
   • Make simpler VLAN management.

Step 2: Set Up NS3

1. Install NS3:

git clone https://gitlab.com/nsnam/ns-3-dev.git

cd ns-3-dev

./ns3 configure –enable-examples –enable-tests

./ns3 build

1. Verify Installation: Confirm installation by executing an example script:

./ns3 run examples/tutorial/first

Step 3: Plan VTP Implementation

1. Core Components:
   • VLAN Database: Saves VLAN sets up like ID, name.
   • VTP Advertisements: Transmit VLAN configurations periodically.
   • VTP Modes: Describe the behavior of VTP modes like server, client, and transparent modes.
2. Workflow:
   • Set VLAN database on the switches.
   • Set up every single switch including a VTP mode.
   • Transmit VTP advertisements periodically.
   • Modernize VLAN database according to the received advertisements.

Step 4: Implement VTP in NS3

Step 4.1: Define the VTP Protocol Class

To replicate the behaviour of VTP, we need to prolong the NS3 Application class:

#include “ns3/application.h”

#include <map>

#include <string>

using namespace ns3;

class VtpApplication : public Application {

public:

static TypeId GetTypeId(void);

VtpApplication();

virtual ~VtpApplication();

void SetMode(std::string mode);

void AddVlan(uint16_t vlanId, std::string vlanName);

void StartVtp();

private:

void SendVtpAdvertisement();

void ReceiveVtpAdvertisement(Ptr<Packet> packet);

std::string m_mode; // VTP mode: server, client, transparent

std::map<uint16_t, std::string> m_vlanDatabase; // VLAN ID -> VLAN Name

Ptr<Socket> m_socket;

};

Step 4.2: Implement Core Functions

• Set VTP Mode: Set up the behavior of switch.

void VtpApplication::SetMode(std::string mode) {

m_mode = mode;

}

• Add VLAN: Enable VLAN creation or alteration for server mode only.

void VtpApplication::AddVlan(uint16_t vlanId, std::string vlanName) {

if (m_mode == “server”) {

m_vlanDatabase[vlanId] = vlanName;

}

}

• Start VTP: Start the periodic VTP commercials.

void VtpApplication::StartVtp() {

if (m_mode == “server” || m_mode == “client”) {

Simulator::Schedule(Seconds(10.0), &VtpApplication::SendVtpAdvertisement, this);

}

}

• Send VTP Advertisement: Transmit the VLAN database for advertisement.

void VtpApplication::SendVtpAdvertisement() {

Ptr<Packet> packet = Create<Packet>();

// Serialize VLAN database into packet

for (const auto &entry : m_vlanDatabase) {

// Add VLAN ID and name to the packet

}

m_socket->Send(packet);

Simulator::Schedule(Seconds(10.0), &VtpApplication::SendVtpAdvertisement, this);

}

• Receive VTP Advertisement: Depends on the received advertisements, we need to modernize the VLAN database.

void VtpApplication::ReceiveVtpAdvertisement(Ptr<Packet> packet) {

if (m_mode == “client” || m_mode == “server”) {

std::map<uint16_t, std::string> receivedDatabase;

// Deserialize the packet into receivedDatabase

for (const auto &entry : receivedDatabase) {

if (m_vlanDatabase.find(entry.first) == m_vlanDatabase.end()) {

m_vlanDatabase[entry.first] = entry.second; // Update database

}

}

}

}

Step 5: Register the Application

Enrol the application including TypeId system in NS3:

TypeId VtpApplication::GetTypeId(void) {

static TypeId tid = TypeId(“ns3::VtpApplication”)

.SetParent<Application>()

.SetGroupName(“Applications”)

.AddConstructor<VtpApplication>();

return tid;

}

Step 6: Integrate into a Simulation

1. Simulation Script Example:

#include “ns3/internet-stack-helper.h”

#include “ns3/vtp-application.h”

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

NodeContainer switches;

switches.Create(3); // Three switches

PointToPointHelper p2p;

p2p.SetDeviceAttribute(“DataRate”, StringValue(“1Gbps”));

p2p.SetChannelAttribute(“Delay”, StringValue(“2ms”));

// Connect switches

p2p.Install(switches.Get(0), switches.Get(1));

p2p.Install(switches.Get(1), switches.Get(2));

InternetStackHelper stack;

stack.Install(switches);

// Configure VTP on switches

Ptr<VtpApplication> switch1App = CreateObject<VtpApplication>();

switch1App->SetMode(“server”);

switch1App->AddVlan(10, “Sales”);

switch1App->AddVlan(20, “Engineering”);

switch1App->SetNode(switches.Get(0));

Ptr<VtpApplication> switch2App = CreateObject<VtpApplication>();

switch2App->SetMode(“client”);

switch2App->SetNode(switches.Get(1));

Ptr<VtpApplication> switch3App = CreateObject<VtpApplication>();

switch3App->SetMode(“transparent”);

switch3App->SetNode(switches.Get(2));

Simulator::Run();

Simulator::Destroy();

return 0;

}

Step 7: Test and Debug

1. Enable Logging: Make use of NS3 logging for debugging the protocol:

export NS_LOG=”VtpApplication=level_all|prefix_time”

./ns3 run my-simulation

1. Verify VLAN Consistency:
   • Make sure that every client inherits the updates from the server.
   • Confirm dynamic VLAN integration or elimination within server mode.

Step 8: Extend and Optimize

1. Enhancements:
   • Execute the VTP pruning for minimizing the unnecessary traffic.
   • Integrate support for VTP versioning, making sure compatibility.
2. Performance Testing:
   • Replicate the performance of protocol testing in larger switch networks.
   • Estimate protocol overhead and synchronization time.

Here, step-by-step implementation process of VLAN Trunking Protocol has been successfully completed by leveraging NS3 simulation tool. We are ready to expand on this if required.