How to Simulate Border Gateway Protocol Projects Using NS3

To simulate the Border Gateway Protocol (BGP) using NS3, we normally require to combine an external routing software like Quagga or FRRouting (FRR). These are real-world routing software suites, which support BGP and can be run in an NS3 simulation using NS3-DCE (Direct Code Execution). This configure permits to replicate an inter-domain routing (e.g., routing between different autonomous systems) using BGP in the NS3 environment. Now, we distribute simple guide on how we can replicate BGP projects in NS3:

Steps to Simulate BGP in NS3:

1. Install NS3 and NS3-DCE: Initially, we install NS3 with DCE to permit to run real-world routing applications such as Quagga or FRRouting in the NS3 simulation environment.
2. Install Quagga or FRRouting: Install Quagga or FRRouting (FRR) that are open-source routing software suites, which support BGP.
3. Create a Network Topology in NS3: Describe a basic network of routers are denoting various Autonomous Systems (ASes). Connect these routers using Point-to-Point (P2P) links to replicate the BGP inter-domain communication.
4. Configure BGP Using Quagga or FRRouting: We will also require to make BGP configuration files (e.g., bgpd.conf) for each router to describe their AS number and BGP neighbors. These configuration files will be utilised by Quagga or FRRouting to configure BGP peering relationships.
5. Use NS3-DCE to Run Quagga/FRR: We can use the NS3-DCE to run Quagga or FRR in the NS3 simulation. It will permit NS3 to replicate the behaviour of BGP by running real BGP software inside the NS3 simulation.
6. Set Up Traffic Generating Applications: Utilise UDP or TCP applications in NS3 to replicate traffic among the customer devices that will traverse the replicated BGP network.
7. Run the Simulation and Analyze the Results: After configuring the BGP peering relationships and traffic applications, then we run the simulation to estimate how BGP manages an inter-domain routing.

Example: Simulating BGP in NS3 Using Quagga

The following is an instance of how to replicate BGP in NS3 by incorporating Quagga using NS3-DCE:

Step-by-Step Example:

Step 1: Install NS3 and NS3-DCE

Make certain NS3 and DCE (Direct Code Execution) are installed. Then we can install NS3 and DCE using the below commands (for Ubuntu):

sudo apt-get install ns3 ns3-dce

Step 2: Install Quagga

Quagga can be installed using the following command:

sudo apt-get install quagga

Instead, we can install FRRouting (FRR) that also supports BGP.

Step 3: Define the Network Topology in NS3

In this sample, we mimic two autonomous systems (AS1 and AS2) connected through a BGP peering session.

#include “ns3/core-module.h”

#include “ns3/network-module.h”

#include “ns3/internet-module.h”

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

#include “ns3/dce-module.h”

#include “ns3/applications-module.h”

using namespace ns3;

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

{

// Step 1: Create nodes for the two ASes

NodeContainer as1Routers, as2Routers;

as1Routers.Create (2); // AS1: Two routers

as2Routers.Create (2); // AS2: Two routers

NodeContainer linkNodes = NodeContainer (as1Routers.Get(1), as2Routers.Get(0));

// Step 2: Create point-to-point links between routers

PointToPointHelper p2p;

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

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

NetDeviceContainer devices1 = p2p.Install (as1Routers);

NetDeviceContainer devices2 = p2p.Install (as2Routers);

NetDeviceContainer linkDevices = p2p.Install (linkNodes);

// Step 3: Install the Internet stack on routers

InternetStackHelper internet;

internet.Install (as1Routers);

internet.Install (as2Routers);

// Step 4: Assign IP addresses

Ipv4AddressHelper ipv4;

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

Ipv4InterfaceContainer ifc1 = ipv4.Assign (devices1);

ipv4.SetBase (“10.2.1.0”, “255.255.255.0”);

Ipv4InterfaceContainer ifc2 = ipv4.Assign (devices2);

ipv4.SetBase (“192.168.1.0”, “255.255.255.0”);

Ipv4InterfaceContainer ifcLink = ipv4.Assign (linkDevices);

// Step 5: Configure Quagga BGP routers using DCE

DceManagerHelper dceManager;

dceManager.Install (as1Routers);

dceManager.Install (as2Routers);

QuaggaHelper quagga;

quagga.EnableBgp (as1Routers.Get (0), “65001”); // Router in AS1 with AS number 65001

quagga.EnableBgp (as1Routers.Get (1), “65001”);

quagga.EnableBgp (as2Routers.Get (0), “65002”); // Router in AS2 with AS number 65002

quagga.EnableBgp (as2Routers.Get (1), “65002”);

// Step 6: Set up BGP peering between AS1 and AS2

quagga.AddBgpNeighbor (as1Routers.Get (1), “192.168.1.2”, “65002”);

quagga.AddBgpNeighbor (as2Routers.Get (0), “192.168.1.1”, “65001”);

// Step 7: Set up traffic applications

UdpEchoServerHelper echoServer (9);

ApplicationContainer serverApps = echoServer.Install (as2Routers.Get (1));  // Server in AS2

serverApps.Start (Seconds (1.0));

serverApps.Stop (Seconds (10.0));

UdpEchoClientHelper echoClient (ifc2.GetAddress (1), 9);

echoClient.SetAttribute (“MaxPackets”, UintegerValue (1));

echoClient.SetAttribute (“Interval”, TimeValue (Seconds (1.0)));

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

ApplicationContainer clientApps = echoClient.Install (as1Routers.Get (0)); // Client in AS1

clientApps.Start (Seconds (2.0));

clientApps.Stop (Seconds (10.0));

// Step 8: Run the simulation

Simulator::Stop (Seconds (10.0));

Simulator::Run ();

Simulator::Destroy ();

return 0;

}

Step 4: BGP Configuration Files (Quagga)

Each router will be needed a bgpd.conf file for BGP configuration. Following is an example bgpd.conf for a router in AS1:

router bgp 65001

bgp router-id 10.1.1.1

neighbor 192.168.1.2 remote-as 65002

For a router in AS2, the configuration would observe like this:

router bgp 65002

bgp router-id 10.2.1.1

neighbor 192.168.1.1 remote-as 65001

These configuration files are describe the AS number and the BGP neighbor relationships among the routers in various ASes.

Step 5: Use DCE to Run BGP

To run Quagga inside NS3, we want to utilise the DCEManagerHelper to handle the Quagga processes inside the NS3 simulation. This integration enables to run actual BGP daemons in the simulation.

Performance Metrics to Analyze:

1. BGP Convergence Time: Evaluate the time it takes for BGP to ascertain peering sessions and populate the routing tables.
2. Route Propagation: Investigate how routes are propagated among the various ASes using BGP.
3. Packet Delivery Ratio (PDR): Compute the percentage of effectively delivered packets.
4. Latency: Assess the delay experienced by packets traveling among the ASes.

Running the Simulation:

1. Build the NS3 Script: We can use the below commands to construct and run the simulation:

./waf configure

./waf build

./waf –run bgp-simulation

1. Analyze the Results: The simulation will generate records, which include BGP route exchanges. Also we can be used Wireshark to investigate the packet exchanges and examine BGP messages.

Extending the Simulation:

1. BGP Policies: Execute the BGP routing policies like route filtering, AS-path manipulation, or local preference to replicate more complex BGP scenarios.
2. Multiple Autonomous Systems: Enlarge the topology to consist of numerous ASes to replicate a large-scale BGP network.
3. BGP Route Reflectors: Mimic BGP Route Reflectors to handle the large networks with minimized BGP peering requirements.

Here, we thoroughly expounded the simple as well as essential procedure with examples and step-by-step instance process on how to approach and replicate Border Gateway Protocol projects using the simulation environment NS3. If you have any doubt feel free to ask, we will clear it. We offer tailored solutions and assist you with comparative analysis. For simulating Border Gateway Protocol projects using the NS3 tool, feel free to reach out to phdprime.com. Share your research details with us, and we’ll provide prompt assistance.