Understanding the Internet's Networking Model for Modern DevOps

Learning Objectives

By the end of this chapter, you should be able to:

• Explain what the TCP/IP model is and why it became the foundation of the modern Internet.
• Understand the four layers of the TCP/IP model.
• Compare the TCP/IP model with the OSI model.
• Explain encapsulation and decapsulation using the TCP/IP model.
• Understand how Linux, Docker, Kubernetes, AWS, Azure, and Google Cloud implement TCP/IP networking.
• Recognize why DevOps engineers should understand both the OSI and TCP/IP models.

Introduction

Throughout this handbook, you've learned networking using the OSI (Open Systems Interconnection) Model.

The OSI model is an excellent educational framework because it divides networking into seven logical layers, making it easier to understand the responsibilities of each part of a network.

However, in real-world production environments—including the Internet, cloud platforms, Linux servers, Docker containers, and Kubernetes clusters—the TCP/IP Model is the networking model that is actually implemented.

As a DevOps engineer, you'll often use the OSI model to troubleshoot problems conceptually, while relying on the TCP/IP model to understand how modern systems communicate.

What Is the TCP/IP Model?

The TCP/IP (Transmission Control Protocol / Internet Protocol) Model is the suite of networking protocols that enables devices around the world to communicate over interconnected networks.

It was developed during the 1970s as part of research funded by the U.S. Department of Defense to create resilient computer networks. Its practical design and successful adoption led it to become the foundation of the modern Internet.