This book is for those people preparing for the CCNA exam, whether through self study, on-the-job training and practice. There are also some handy hints and tips along the way to hopefully make life a bit easier for you in this endeavor. This book will also be useful to network professionals who are not preparing for the CCNA exam yet need a quick reference to reinforce or refresh networking concepts and commands. It is small enough that you will find it easy to carry around with you. Big heavy textbooks might look impressive on your bookshelf in your office, but can you really carry them all around with you when you are working in some server room or equipment closet somewhere?