How to Implement Next Generation Firewalls in NS2

To implement Next Generation Firewalls (NGFWs) in NS2 has includes to incorporate the cutting edge security characteristics into the existing network simulator structure. NGFWs deliver a deeper level of security related to traditional firewalls by integrating the stateful packet filtering with features such as application awareness, intrusion detection, and content inspection. The given below is detailed approach to implement the next generation firewalls in ns2:

Step-by-Step Implementation:

  1. Identify Key Features of NGFW

Before execution, recognize the core structures of a Next Generation Firewall:

  • Deep Packet Inspection (DPI): Examine the data within the packet beyond headers.
  • Application Control: Control traffic based on the application generating it, not just port numbers.
  • Intrusion Prevention System (IPS): Identify and avoid attacks in real-time.
  • SSL Decryption: Examine SSL/TLS encrypted traffic.
  • URL Filtering: Block access to mischievous or unwanted websites.
  • Identity Awareness: Incorporate with user authentication systems to implement policies.
  1. Set Up NS2:
  • Install NS2 on your system and configure the simple environment.
  • Understand yourself with adjusting C++ code for packet processing and TCL for describing network scenarios.
  1. Define Simulation Scenario:
  • Generate a network scenario in which the NGFW will be placed among nodes such as  mobile devices, servers, etc.
  • Describe the network topology and stipulate the traffic sources (TCP/UDP, multimedia, etc.).
  1. Implement Key NGFW Features:
  2. a) Deep Packet Inspection (DPI):

DPI examines packet contents further than the header that has application layer data to identify anomalies, malicious content, or policy violations.

  • Adapt the packet structure in NS2 to examine payloads, usually found in packet.h.
  • Execute a function in C++ that does deep packet inspection, validating for signatures of known attacks or policy violations.
  • In TCL script, mimic different kinds of traffic, and utilize the DPI logic to examine the payload.

Example DPI code (in C++):

void Firewall::inspectPacket(Packet* pkt) {

hdr_cmn* hdr = hdr_cmn::access(pkt);

if (hdr->ptype() == PT_TCP || hdr->ptype() == PT_UDP) {

// Extract packet payload

char* payload = pkt->accessdata();

// Inspect payload for malicious patterns (e.g., SQL injection, XSS, etc.)

if (strstr(payload, “malicious-pattern”) != NULL) {

dropPacket(pkt);  // Block packet if malicious pattern detected

}

}

}

  1. b) Application Control:

Control network traffic according to the application generating it. For instance, blocking peer-to-peer applications or containing specific social media traffic.

  • Add an application-layer inspection mechanism. Adapt the packet processing logic in C++ to identify packets by measuring headers and payloads to regulate the application type such as HTTP, FTP.
  • According to application type, set rules to permit or block the traffic.

Example (in C++):

void Firewall::blockApplication(Packet* pkt) {

hdr_ip* iph = hdr_ip::access(pkt);

if (iph->daddr() == “social-media-server-ip”) {

dropPacket(pkt);  // Block social media traffic

}

}

  1. c) Intrusion Prevention System (IPS):

The NGFW can actively avoid known attacks using an Intrusion Prevention System (IPS).

  • Execute or incorporate an existing IPS module to identify attack signatures like SQL injection, DDoS attempts, or malware patterns.
  • Compose a C++ function that mimics signature-based or anomaly-based detection within the NGFW, dropping or flagging malicious packets.
  1. d) SSL Decryption:

To examine encrypted SSL/TLS traffic, we must mimic the decryption process.

  • For simplicity, we can simulate SSL traffic by encrypting and decrypting payloads in C++ using simple encryption techniques such as AES.
  • Execute functions to decode and examine SSL traffic.
  1. e) URL Filtering:

The NGFW can block traffic to or from certain URLs, often based on reputation databases.

  • Generate a simple filtering mechanism in NS2 by validating the destination IP address against a blacklist of malicious or unwanted URLs.
  • Adapt the packet processing logic to drop packets destined for blocked URLs.

Example:

void Firewall::filterURL(Packet* pkt) {

hdr_ip* iph = hdr_ip::access(pkt);

if (iph->daddr() == “blocked-website-ip”) {

dropPacket(pkt);  // Block access to specific website

}

}

  1. f) Identity Awareness:

Implement policies according to user identity. In NS2, we can mimic identity-based policies by allocating IP addresses to user identities.

  • Appliance a mapping of user identities to their IP addresses or utilizes MAC addresses.
  • Compose rules to implement different firewall policies according to the identity.
  1. Modify NS2 Codebase:
  • Packet Header Changes: Adapt packet.h to store additional information needed for application control, DPI, SSL decryption, etc.
  • Protocol Changes: Adjust routing protocols such as AODV or DSR to communicate with the NGFW functions.
  • TCL Script Changes: Mimic a real-world network with different kinds of traffic, application traffic, and user identities. Incorporate NGFW processing at key network points.
  1. Code Implementation in NS2:

Example TCL Script for NGFW Implementation:

# Create simulator

set ns [new Simulator]

# Define firewall between nodes

set node0 [$ns node]

set node1 [$ns node]

set node2 [$ns node]  ;# Simulate a firewall node

# Define NGFW at node2

$ns at 1.0 “node2 install-firewall”

# Define traffic (HTTP, FTP, etc.)

set ftp [new Application/FTP]

$ftp attach-agent $node0

# Setup malicious traffic

$ns at 2.0 “$ftp start”

  1. Simulate Different Threat Scenarios:
  • Malicious Traffic: Mimic traffic with payloads containing known malware or attack signatures, and validate that the NGFW identifies and blocks the traffic.
  • SSL Traffic: Mimic SSL/TLS traffic and validate SSL decryption functionality.
  • Application Filtering: Create diverse application traffic such as FTP, HTTP and validate application control functionality.
  1. Testing and Evaluation:
  • Execute the NS2 simulation, capture the trace files, and measure on how efficiently the NGFW prevents attacks.
  • Evaluate the logs for blocked traffic, DPI results, and intrusion prevention alerts.
  1. Analysis of Results:
  • Use trace files to evaluate packet flow and firewall effectiveness.
  • The key parameters such as throughput, packet loss, detection rate, and false positives.

We demonstrate how to implement basic Next Generation Firewalls for deeper level security that were executed using NS2 simulator tool. We can extend upon this to include more advanced next generation firewall key features and test different types of scenarios and security measures. We’ve got Next Generation Firewalls set up in the NS2 tool, so hit us up at ns2project.com for help with your project’s performance analysis. Our team is focused on features like application awareness, intrusion detection, and content inspection tailored