Packet Guide to Core Network Protocols

Preface

Trying to find the perfect networking resource or textbook can be a real challenge. Sometimes they are extremely focused on one technology, and thus miss the mark. Or they are extremely broad, covering every networking idea known to man. This book is about something that all networks have in common—the core protocols. Networks have a couple of basic building blocks: routers, switches, access points, and hosts. These building blocks use a particular set of rules when forwarding bits of information from one side of the network to another.

These bits are wrapped up in a neat little package called a packet. Packets have many qualities, but one thing they never do is lie. If a packet is present, it is there because some device or network host put it there. By looking at the packets running on a network and understanding the forces (sometimes good, sometimes evil) that put them there, we can gain a deep understanding of how networks operate and what is happening at a given moment.

This book provides the structure (a.k.a. model) used to formulate network transmissions and then dives into the major protocols populating almost every single network today: Ethernet, Internet Protocol (IP), Address Resolution Protocol (ARP), and the Internet Control Message Protocol (ICMP). But this is not simply a description of the foundation protocols. In each chapter, the protocol is analyzed by examining topologies and the packets generated on actual networks. Wireshark is the tool of choice. It ...