Cloud security has become critical as cloud environments often include resources not managed by the organization but by third-party providers. To mitigate risks, organizations and cloud providers rely on a shared responsibility model to appropriately manage expectations for securing cloud resources. In this five-part series, we will look at how organizations can create a manageable scope for cloud security in key areas such as network boundaries, devices and services that access an organization’s network, access management for all resources, application code, and service and user data. Part 1 focuses on the evolution of network perimeters in modern cloud environments and best practices for securing them. This includes taking inventory of and securing all network entry points, using Zero Trust architecture to restrict access, segmenting networks to control traffic from potentially vulnerable entry points, and getting visibility into all network traffic.