TCP/IP Illustrated, Volume 1: The Protocols
is an excellent text that provides encyclopedic coverage of the TCP/IP protocol suite. What sets this book apart from others on this subject is the fact that the author supplements all of the discussion with data collected via diagnostic programs; thus, it is possible to "watch" the protocols in action in a real situation. Also, the diagnostic tools involved are publicly available; the reader has the opportunity to play along at home. This offers the reader an unparalleled opportunity to really get a feel for the behavior of the protocols in day-to-day operation. TCP/IP Illustrated, Volume 1: The Protocols
features clear discussions and well-designed figures.
Volume two of this series, TCP/IP Illustrated, Volume 2: The Implementation, covers the implementation of TCP/IP. Volume three explores TCP for Transactions, HTTP, NNTP, and the Unix Domain Protocols.