Part I of this book introduces you to the most important topics in TCP/IP networking and data center architecture. Chapter 1 introduces data center architecture evolution and the infrastructure used to create these architectures. Chapter 2 introduces the terms, concepts, and protocols for TCP/IP. Chapter 3 focuses on the links between nearby devices (local area networks). Finally, Chapter 4 focuses on the rules of IP routing, which pull the LAN and WAN links together by forwarding data all the way from one user device to another.