How to Begin Implement a Network Defense in NS3

To begin executing Network Defense using ns3, it has numerous steps to follow and we need to make mechanisms for defending a network versus malicious activities like intrusions, attacks, or unauthorized access. It normally contains replicating defenses such as firewalls, intrusion detection/prevention systems (IDS/IPS), encryption, and traffic filtering.

We will guide you through the following steps to start executing network defense in ns3:

Steps to Begin Implement a Network Defense in NS3

1. Set Up ns3 Environment

1. Install ns3:
   • We can download and install ns3 on the system.
   • Confirm the installation with ./waf –run hello-simulator.
2. Install Required Modules:
   • Make sure that we have all necessary components such as internet, point-to-point, wifi, and applications.

2. Define Defense Objectives

Focus on the project’s goals of network defense:

• Preventive Measures:
  • Obstruct malicious traffic to utilize firewalls or encryption.
• Detect and Respond:
  • Identify intrusions and moderate attacks with IDS/IPS.
• Secure Communication:
  • Execute the encryption for defending sensitive communication data.

3. Set Up Network Topology

1. Create Nodes:
   • Describe nodes for clients, servers, routers, and defense systems in network topology.

NodeContainer nodes;

nodes.Create(4); // Example: Client, Server, Router, Defense Node

1. Configure Connections:
   • Launch connections with the help of PointToPointHelper or WifiHelper.

PointToPointHelper p2p;

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

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

NetDeviceContainer devices = p2p.Install(nodes.Get(0), nodes.Get(1));

1. Assign IP Addresses:

InternetStackHelper internet;

internet.Install(nodes);

Ipv4AddressHelper ipv4;

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

ipv4.Assign(devices);

4. Implement Network Defense Mechanisms

1. Firewalls:
   • According to the IP addresses, ports, or protocols, describe rules to obstruct or permit the traffic.

void FirewallCallback(Ptr<const Packet> packet) {

// Inspect packet headers to filter traffic

PppHeader pppHeader;

packet->PeekHeader(pppHeader);

if (/* malicious IP or port condition */) {

NS_LOG_UNCOND(“Blocked malicious traffic: ” << packet->ToString());

}

}

Config::ConnectWithoutContext(“/NodeList/*/DeviceList/*/MacRx”, MakeCallback(&FirewallCallback));

1. Intrusion Detection System (IDS):
   • Observe traffic using IDS for anomalies or suspicious models.

void IDSCallback(Ptr<const Packet> packet) {

// Detect anomalies in traffic

if (/* suspicious pattern */) {

NS_LOG_UNCOND(“Intrusion detected!”);

}

}

Config::ConnectWithoutContext(“/NodeList/*/ApplicationList/*/$ns3::PacketSink/Rx”, MakeCallback(&IDSCallback));

1. Traffic Encryption:
   • Mimic encrypted interaction by means of integrating custom encryption/decryption logic.

class SecureApplication : public Application {

public:

void StartApplication() override {

// Encrypt outgoing data

// Decrypt incoming data

}

};

1. Rate Limiting:
   • Restrict the rate of traffic for avoiding DoS or DDoS attacks.

void RateLimitCallback(Ptr<const Packet> packet) {

static int packetCount = 0;

packetCount++;

if (packetCount > MAX_PACKETS) {

NS_LOG_UNCOND(“Rate limit reached. Dropping packet.”);

}

}

1. Blacklisting:
   • Sustain a set of malicious IPs to obstruct.

std::set<Ipv4Address> blacklist = {Ipv4Address(“10.1.1.3”)};

if (blacklist.find(packetSourceIP) != blacklist.end()) {

NS_LOG_UNCOND(“Dropped packet from blacklisted IP: ” << packetSourceIP);

}

5. Simulate Attacks

1. Generate Normal Traffic:
   • Make use of UDP or TCP applications to replicate the normal traffic.

UdpEchoServerHelper echoServer(9);

ApplicationContainer serverApps = echoServer.Install(nodes.Get(1));

serverApps.Start(Seconds(1.0));

serverApps.Stop(Seconds(10.0));

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

echoClient.SetAttribute(“MaxPackets”, UintegerValue(100));

echoClient.SetAttribute(“Interval”, TimeValue(Seconds(0.1))); // 10 packets/second

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

ApplicationContainer clientApps = echoClient.Install(nodes.Get(0));

clientApps.Start(Seconds(2.0));

clientApps.Stop(Seconds(10.0));

1. Simulate Malicious Traffic:
   • Establish abnormal traffic like a Denial of Service (DoS) attack.

OnOffHelper attack(“ns3::UdpSocketFactory”, InetSocketAddress(interfaces.GetAddress(1), 9));

attack.SetAttribute(“DataRate”, StringValue(“1Gbps”));

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

ApplicationContainer attackApps = attack.Install(nodes.Get(2)); // Attacker Node

attackApps.Start(Seconds(3.0));

attackApps.Stop(Seconds(10.0));

6. Analyze and Log Results

1. Real-Time Monitoring:
   • During the simulation, record and examine the packet events.

Config::ConnectWithoutContext(“/NodeList/*/DeviceList/*/MacRx”, MakeCallback(&PacketLogger));

void PacketLogger(Ptr<const Packet> packet) {

NS_LOG_UNCOND(“Packet received: ” << packet->ToString());

}

1. Offline Analysis:
   • Seize and examine the records utilizing AsciiTraceHelper or FlowMonitor for offline investigation.

AsciiTraceHelper ascii;

p2p.EnableAsciiAll(ascii.CreateFileStream(“network-defense.tr”));

FlowMonitorHelper flowmon;

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

7. Visualize the Simulation

1. NetAnim:
   • Apply AnimationInterface in NetAnim tools for envisioning the node communications and defense approaches.

AnimationInterface anim(“network-defense.xml”);

1. Graphical Analysis:
   • Transfer records into external tools such as Python, MATLAB, or Excel for visualization.

8. Extend and Optimize

1. Advanced Defense Mechanisms:
   • Execute the advanced mechanisms of defense such as IPSec, TLS, or application-layer firewalls.
2. Machine Learning:
   • For dynamic defenses, we can leverage anomaly detection including ML models.
3. Scalability:
   • Experiment the defenses including various traffic within large-scale networks.

Example Use Cases

• Enterprise Network Security: Defend community resources from external attacks.
• IoT Security: It supports to secure interaction within IoT devices.
• Cybersecurity Training: Replicate the real-world attack and defense situations.

As we discussed earlier regarding how the Network Defense will perform and implement using NS3 simulation tool in this manual and we will deliver additional material about this subject as needed.