The Computer Networks laboratory works and methodical guidelines are designed to help students to acquire knowledge about computer network technologies, network equipment, network design principles, configuration and troubleshooting tasks. Twelve laboratory works are presented in the book. Each laboratory work consists of theoretical material that introduces the object of investigation, laboratory work assignments and methodical guidelines. At the end of each laboratory work the references and review questions and problems are presented. This book is intended for students studying Computer Engineering and Information Systems Engineering courses, also for students studying the subject of computer networks. This publication has been produced with the financial assistance of Europe Social Fund and VGTU (Project No VP1-2.2-ŠMM-07-K-01-047). The book is a part of the project “The Essential Renewal of Undergraduates Study Programs of VGTU Electronics Faculty”.