Part I: Network Theory

Welcome to Part I of Network Fundamentals & Security Exploits. This section builds the foundation you need to understand networks at a deep level—essential knowledge for anyone who wants to work with network security.

What You'll Learn

In this part, we cover the complete landscape of modern networking:

• Network Basics: What networks are, how they evolved, and the types we use today
• Protocol Layers: The OSI model and TCP/IP stack that organize network communication
• Data Link Layer: How devices communicate on local networks (Ethernet, ARP, VLANs)
• Network Layer: IP addressing, routing, and how packets traverse the internet
• Transport Layer: TCP, UDP, and modern protocols like QUIC
• Application Layer: DNS, HTTP, TLS, and protocols users interact with
• Infrastructure: Routers, switches, and the systems that make networks work
• Modern Topics: Wireless, cloud, containers, and software-defined networking

Chapter Overview

How to Approach This Part

If you're new to networking, we recommend reading chapters 1-6 in order, as each builds on the previous. Chapters 7-11 cover specialized topics and can be read based on your interests.

Pro Tip: Each chapter includes "Try It Yourself" exercises. Hands-on practice is the best way to solidify these concepts.