I've been trying to learn about hardware-y side of networking lately, too. Three things I found useful: - Ethernet The Definitive Guide. Part 1 (Introduction

I've been trying to learn about hardware-y side of networking lately, too. Three things I found useful: - Ethernet The Definitive Guide. Part 1 (Introduction) was a good orientation. Part 4 (Switches and Network Design) talks about switches vs routers, for example. - I've reading Network Algorithms. This book is broad investigation into "network application performance" and considers protocols, hardware, network device and network architecture, operating systems and applications. - I've been trying to understand the low-level hardware by building a networking stack from scratch on a FPGA board. I'm using the Digilent Arty Artix-7 board ($99): http://store.digilentinc.com/arty-artix-7-fpga-development-board-for-makers-and-hobbyists/ http://store.digilentinc.com/arty-artix-7-fpga-development-b... I'm now able to send and receive Ethernet packets and I'm now thinking about how to implement higher-level protocols like ARP. Good luck! This is fun stuff.