The paper discusses the fundamental concepts of computer networking, including topologies, infrastructure, network devices, as well as security policies and solutions crucial for data protection. The proper selection of network topologies, devices such as routers, switches, and firewalls, and appropriate addressing ensures efficient network traffic management and access control to sensitive data, which contributes to the stability and security of network infrastructure. Furthermore, the paper focuses on security protocols that enable encryption, authentication, and remote access for both wired and wireless networks. Network design includes both physical and logical elements that enable segmentation and the definition of security zones, based on the principles of confidentiality, integrity, and availability (CIA triad), to achieve optimal protection of the network system. The practical part of the paper involves the implementation and testing of the Snort tool as an Intrusion Detection and Prevention System (IDS/IPS) in a simulated environment. The test results demonstrate the effectiveness of the Snort tool in detecting potential intrusions and provide guidelines for further improvement of network security.