Objective. Network security systems are one of the key players in today's business life. Some networks are private while others are open to the public. Whether your network is private or public, it must be well secured and secure. In this article, we will discuss where network security begins, and describe the general measures taken to secure it.Method. The study is determined by the need to solve the problem of algorithmic and mathematical support for assessing the functional security of a network based on system modeling and finding erroneous positions.Result. Proposed deployment of a private network system that is designed and serves a specific group of people for communication, collaboration and sharing.Conclusion. The proposed methods can be effective in protecting the network from attacks and other security threats. Well-designed corporate policies are critical to defining and controlling access to various parts of the network.