The book: “COMPUTER NETWORKS IN PACKET TRACER FOR INTERMEDIATE USERS” is designed for people who want to expand their skills and knowledge in the field of managing LAN and WAN networks. The reader finds here descriptions and practical exercises on configuring CISCO devices. It is a continuation of the first book with the same title. The authors have adopted the principle: minimum of theory, maximum of practical examples which will enable the reader to learn how to administer ICT networks in many complex device configurations without the need to purchase expensive CISCO equipment. The content of the book covers the basics of configuring protocols, services and network techniques such as: dynamic routing RIP, EGIRP, OSPF, eBGP, static routing, access control lists VoIP, STP, RS,VTP, FRAME RELAY, PPP, PAP and CHAP authentication RADIUS, NETFLOW, NAT, L2NAT, VPN tuneling. This part also includes configuring multilayer switches 3560-24PS and 3650-24PS. The authors of this book are an intergenerational and interdisciplinary team. Talented student of the Communications School Complex in Gdansk Damian Strojek. His passion is computer networks, and he holds certifications CCNA R&S and CCNA Security. Jerzy Kluczewski, a long-time CISCO CCNA Academy instructor. He already has several book publications to his credit about the Packet Tracer simulator. He gained his experience while working in industry and is currently a lecturer at the Gdansk School of Banking. Translation: a very talented student of applied linguistics at Silesian University in Katowice – Julia Skutela. She has been studying English and Russian to become a professional translator. Eager to expand her knowledge and building a workshop of the translator she has decided to raise up to the challenge of translating the following book into English.