This document is designed to give the reader a reasonable working knowledge of TCP/IP subnetting, addressing, and routing. It is not intended to be complete, or to cover all issues. This is targeted toward LAN administrators just moving to TCP/IP, however it should help anyone who wants to know a little (more) about how TCP/IP works. This document does not, generally, apply to dial-up SLIP/PPP connections. It also has a subnet calculator at the end.