How to Begin Implement Network DNS Management in NS3

To implement the network DNS management in ns-3 has contain the replicate a Domain Name System (DNS) that resolves for human-readable domain names for IP addresses. This replication can be involves the build a DNS servers, handling the DNS queries and responses, and examine the DNS congestion in the network.

Here’s how to begin implementing network DNS management in ns-3:

Steps to Begin Implement Network DNS Management in NS3

1. Understand DNS Management

• DNS Components:
  • DNS Server: Save and determine the domain name records.
  • DNS Client: Forwarding the queries to resolve the domain names.
• Types of Queries:
  • A Records: IPv4 address resolution.
  • AAAA Records: IPv6 address resolution.
  • CNAME Records: Resolution for canonical name.
• Use Cases:
  • Experiment with DNS congestion flow and its impact of network performance.
  • It replicates the DNS failures or attacks for instance DNS spoofing, amplification.

2. Set up ns-3 Environment

• Install ns-3 and prove the installation:

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

cd ns-3-dev

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

./ns3 build

• Validate the setting:

./ns3 run hello-simulato

3. Design DNS Management Simulation

• Scenario: It replicates the DNS server and numerous clients are querying for domain names.
• Network Topology:
  • DNS Server: Central node has determining the domain names.
  • DNS Clients: Nodes are forwarding queries to the server.
  • Routers or Switches: Optional intermediaries for network segmentation.

4. Steps to Implement DNS Management

(a) Create Nodes

• Express the nodes for the DNS server and clients:

NodeContainer dnsServer, dnsClients;

dnsServer.Create(1);  // Single DNS server

dnsClients.Create(3); // Three DNS clients

(b) Set Up Network Links

• Use PointToPointHelper or CsmaHelper to link nodes:

PointToPointHelper p2p;

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

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

NetDeviceContainer serverDevices, clientDevices;

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

serverDevices.Add(p2p.Install(NodeContainer(dnsServer.Get(0), dnsClients.Get(i))));

}

(c) Install Internet Stack

• For all nodes are install in the Internet stack:

InternetStackHelper stack;

stack.Install(dnsServer);

stack.Install(dnsClients);

(d) Assign IP Addresses

• It allocate the IP addresses for all devices:

Ipv4AddressHelper address;

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

std::string subnet = “10.1.” + std::to_string(i + 1) + “.0”;

address.SetBase(subnet.c_str(), “255.255.255.0”);

address.Assign(serverDevices.Get(i));

}

5. Implement DNS Query and Response Logic

(a) DNS Server Application

• Build a custom DNS server application which attends for DNS queries and forwarding the responses.
• Example:

class DnsServerApp : public Application {

public:

void StartApplication() override {

Ptr<Socket> socket = Socket::CreateSocket(GetNode(), UdpSocketFactory::GetTypeId());

InetSocketAddress localAddress(Ipv4Address::GetAny(), 53);

socket->Bind(localAddress);

socket->SetRecvCallback(MakeCallback(&DnsServerApp::HandleQuery, this));

}

void HandleQuery(Ptr<Socket> socket) {

Ptr<Packet> queryPacket = socket->Recv();

NS_LOG_UNCOND(“Received DNS query at ” << Simulator::Now().GetSeconds() << ” seconds”);

// Simulate DNS response

Ptr<Packet> responsePacket = Create<Packet>(100); // Example response size

socket->Send(responsePacket);

NS_LOG_UNCOND(“Sent DNS response at ” << Simulator::Now().GetSeconds() << ” seconds”);

}

};

Ptr<DnsServerApp> dnsServerApp = CreateObject<DnsServerApp>();

dnsServer.Get(0)->AddApplication(dnsServerApp);

dnsServerApp->SetStartTime(Seconds(1.0));

dnsServerApp->SetStopTime(Seconds(10.0));

(b) DNS Client Application

• Generate a DNS for client application which forward the queries in server:

class DnsClientApp : public Application {

public:

void StartApplication() override {

Ptr<Socket> socket = Socket::CreateSocket(GetNode(), UdpSocketFactory::GetTypeId());

InetSocketAddress serverAddress(Ipv4Address(“10.1.1.1”), 53); // Example server address

socket->Connect(serverAddress);

// Send periodic DNS queries

Simulator::Schedule(Seconds(2.0), &DnsClientApp::SendQuery, this, socket);

}

void SendQuery(Ptr<Socket> socket) {

Ptr<Packet> queryPacket = Create<Packet>(50); // Example query size

socket->Send(queryPacket);

NS_LOG_UNCOND(“Sent DNS query at ” << Simulator::Now().GetSeconds() << ” seconds”);

// Schedule the next query

Simulator::Schedule(Seconds(2.0), &DnsClientApp::SendQuery, this, socket);

}

};

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

Ptr<DnsClientApp> dnsClientApp = CreateObject<DnsClientApp>();

dnsClients.Get(i)->AddApplication(dnsClientApp);

dnsClientApp->SetStartTime(Seconds(1.0));

dnsClientApp->SetStopTime(Seconds(10.0));

}

6. Monitor and Analyze DNS Traffic

• Use to analyze DNS congestion for FlowMonitor:

FlowMonitorHelper flowmon;

Ptr<FlowMonitor> monitor = flowmon.InstallAll();

Simulator::Run();

monitor->SerializeToXmlFile(“dns-traffic.xml”, true, true);

• Use custom logging for monitor the DNS queries and responses:

NS_LOG_UNCOND(“DNS query received: ” << queryPacket->GetSize() << ” bytes”);

7. Complete Example Code

Below is a comprehensive sample for replicate DNS management:

#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”

#include “ns3/flow-monitor-module.h”

using namespace ns3;

class DnsServerApp : public Application {

public:

void StartApplication() override {

Ptr<Socket> socket = Socket::CreateSocket(GetNode(), UdpSocketFactory::GetTypeId());

InetSocketAddress localAddress(Ipv4Address::GetAny(), 53);

socket->Bind(localAddress);

socket->SetRecvCallback(MakeCallback(&DnsServerApp::HandleQuery, this));

}

void HandleQuery(Ptr<Socket> socket) {

Ptr<Packet> queryPacket = socket->Recv();

NS_LOG_UNCOND(“Received DNS query at ” << Simulator::Now().GetSeconds() << ” seconds”);

Ptr<Packet> responsePacket = Create<Packet>(100);

socket->Send(responsePacket);

NS_LOG_UNCOND(“Sent DNS response at ” << Simulator::Now().GetSeconds() << ” seconds”);

}

};

class DnsClientApp : public Application {

public:

void StartApplication() override {

Ptr<Socket> socket = Socket::CreateSocket(GetNode(), UdpSocketFactory::GetTypeId());

InetSocketAddress serverAddress(Ipv4Address(“10.1.1.1”), 53);

socket->Connect(serverAddress);

Simulator::Schedule(Seconds(2.0), &DnsClientApp::SendQuery, this, socket);

}

void SendQuery(Ptr<Socket> socket) {

Ptr<Packet> queryPacket = Create<Packet>(50);

socket->Send(queryPacket);

NS_LOG_UNCOND(“Sent DNS query at ” << Simulator::Now().GetSeconds() << ” seconds”);

Simulator::Schedule(Seconds(2.0), &DnsClientApp::SendQuery, this, socket);

}

};

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

CommandLine cmd;

cmd.Parse(argc, argv);

NodeContainer dnsServer, dnsClients;

dnsServer.Create(1);

dnsClients.Create(3);

PointToPointHelper p2p;

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

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

NetDeviceContainer devices;

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

devices.Add(p2p.Install(NodeContainer(dnsServer.Get(0), dnsClients.Get(i))));

}

InternetStackHelper stack;

stack.Install(dnsServer);

stack.Install(dnsClients);

Ipv4AddressHelper address;

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

address.Assign(devices);

Ptr<DnsServerApp> dnsServerApp = CreateObject<DnsServerApp>();

dnsServer.Get(0)->AddApplication(dnsServerApp);

dnsServerApp->SetStartTime(Seconds(1.0));

dnsServerApp->SetStopTime(Seconds(10.0));

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

Ptr<DnsClientApp> dnsClientApp = CreateObject<DnsClientApp>();

dnsClients.Get(i)->AddApplication(dnsClientApp);

dnsClientApp->SetStartTime(Seconds(1.0));

dnsClientApp->SetStopTime(Seconds(10.0));

}

FlowMonitorHelper flowmon;

Ptr<FlowMonitor> monitor = flowmon.InstallAll();

Simulator::Run();

monitor->SerializeToXmlFile(“dns-traffic.xml”, true, true);

Simulator::Destroy();

return 0;

}

8. Validate and Extend

• Validate: Use logs or the FlowMonitor outcomes to validate the DNS query/response behavior.
• Extend:
  • Enhance the DNS for caching or load balancing.
  • It replicates the DNS failures or attacks for sample spoofing, DDoS.

Now, we successfully implemented and calculated the DNS management in ns3 tool. We will effort the comprehensive overview of how DNS simulated in various environment.