Learn to Subnet
A FREE site with detailed instructions on how to subnet.

Randall S. Benn's Cisco Systems in a Nutshell
Page full of links to hard to find places on the Cisco Website. Nice page but a little over commercialized for my taste.

The Net3 Group IP Subnet Calculator
A top notch Subnet calculator from the Net3 Group Inc.

ICMP Type Codes
Type codes for ICMP

List of TCP/UDP Well Known Port Numbers
List of Well known port numbers for the TCP/UDP protocols.

The CIDR Report
A weekly report on the effective use of CIDR on the Internet (very cool)

Understanding IP Addressing
3COM Document about IP addressing and subnetting.

Introduction to BGP
Introduction to BGP presentation by Paul Ferguson of Cisco Systems

Charles Spurgeon Ethernet Web Site
This site provides extensive information about Ethernet (IEEE 802.3) local area network (LAN) technology. Including the original 10 Megabit per second (Mbps) system, the 100 Mbps Fast Ethernet system (802.3u), and the Gigabit Ethernet system (802.3z).

ATM Tutorial
A tutorial on ATM

ISDN Tutorial
ISDN Tutorial

Novell Info about IPX
Novells all you ever need to know about IPX stuff, approx 60 pgs

TCP over Satellite Links
How to calculate TCP bandwidth over a satellite connection