🚀 Building the Internet Emulator

📌 Description

Border Gateway Protocol (BGP) is the standard exterior gateway protocol designed to exchange routing and reachability information among autonomous systems (AS) on the Internet. It is the glue of the Internet and a fundamental part of its infrastructure.

Project Components

The project provides fundamental Internet components implemented as Python classes, including:

• Internet exchanges
• Autonomous systems (AS)
• BGP routers
• DNS infrastructure
• A range of other services

These components serve as modular building blocks that users can assemble to construct their own programmable Internet emulations.

---

🚀 Getting Started

✅ Step 1: Install the Necessary Software

To run the emulator, ensure the following are installed on your system:

• Docker
• Docker Compose
• Python 3

---

📂 Step 2: Set Up the Project

To enable the emulator code:

1. Add the project's root folder to the PYTHONPATH environment variable.

2. Run the following command inside the root directory to temporarily set it:

   source development.env
   

🌐 Step 3: Set Up the Proxy (Optional)

Only needed if you're having issues downloading Docker images (e.g., you're in Mainland China).

The emulator pulls Docker images from Docker Hub. If you encounter slow or failed downloads:

• Use a Docker Hub proxy
  📘 Follow the proxy setup instructions to configure your environment.

• If proxies are slow or unreliable, we recommend building the Docker images locally.
  🛠️ Follow the local build instructions to build images directly on your machine.

---

✅ If you're not facing any Docker Hub access issues, you can safely skip this step.

🛠️ Languages and Utilities Used

• 🐍 Python
• 🖥️ Bash
• 📦 Docker and Docker Compose
• 🌍 BIRD Internet Routing Daemon
• 📡 tcpdump
• 🏗️ Linux Command-Line Utilities
• 🏴‍☠️ Ubuntu 20.04 VM

---

💻 Environments Used

• 🏢 Windows 10 (21H2)

---

📜 Program Walk-through

🔹 Task 1: Stub Autonomous System

• Task 1.a: Understanding AS-155’s BGP Configuration
• Task 1.b: Observing BGP UPDATE Messages
• Task 1.c: Experimenting with Large Communities
• Task 1.d: Configuring AS-180

🔹 Task 2: Transit Autonomous System

• Task 2.a: Experimenting with IBGP
• Task 2.b: Experimenting with IGP

🔹 Task 3: Path Selection

🔹 Task 4: IP Anycast

---

🌐 Key Learnings:

• Understood how stub and transit ASes are configured and how they influence BGP routing behavior.
• Simulated prefix hijacking attacks, demonstrating BGP’s vulnerabilities and the consequences of malicious route advertisement.
• Analyzed BGP path selection, UPDATE messages, IBGP vs. EBGP, and the use of Large Communities for advanced policy control.
• Explored the real-world application of IP Anycast, showcasing how the same IP can be advertised from multiple geographic locations.

---

🔐 Security Insight:

BGP is powerful—but not without flaws. Through this lab, we learned:

• How misconfigurations or malicious behavior can lead to route hijacking or traffic interception.
• The importance of deploying RPKI (Resource Public Key Infrastructure) and BGP monitoring tools to improve routing security.
• The need for coordination among network operators to ensure a resilient Internet backbone.

✅ Conclusion

This lab provided a comprehensive hands-on exploration of the Border Gateway Protocol (BGP)—the protocol that binds the global Internet together by enabling communication between Autonomous Systems (ASes).

---