The tutorial contains theoretical information and step-by-step practical recommendations for organizing local computer networks. Along with setting up experiments in real networks, it is proposed to use software that allows you to simulate the structure and study processes in a computer network. Practical issues of configuring network interfaces and working with utilities are considered using a cross-platform approach. Intended for students and teachers studying and working in the areas and specialties of the field of knowledge 0501 "Informatics and Computer Science". UDC 004.7