A system generates network perimeter for an organization based on the connection data. The system builds a model, for example, a machine learning based model configured to receive a network zone as input and output a score indicating security of the network zone. The system receives information describing connection requests received from client devices associated with the organization. The system adjusts parameters of the machine learning based model based on information describing the connection requests. The adjusting of the machine learning based model improves the accuracy of prediction based on the information describing the connection requests. The system determines a network perimeter for the organization using the machine learning based model. The network perimeter may be used for implementing a network policy for the organization based on the determined network perimeter.