Special Edition Using TCP/IP provides the information you need to network systems using the standard cross-platform system that's the backbone of the internet. It covers such topics as: TCP/IP Overview, Creating a TCP/IP Intranet, OSI Network Layers, TCP/IP Addressing, TCP/IP Traffic, Common Protocols Explained, TCP/IP and the Internet, Network Security & Management, Diagnosing Problems, and the Future of TCP/IP.
This book taught me pretty much everything I know about TCP/IP and the protocols built on top of it. The vast majority of which is still valid and in use today with little change.