Cloud Security Fundamentals

Chapter 14Cloud Network Security

Modern cloud environments demand rigorous approaches to network security that go far beyond traditional perimeter defenses. As enterprises adopt distributed architectures, ephemeral workloads, and hybrid connectivity, the network becomes both an operational backbone and a critical vulnerability to attack. This chapter examines how cloud-native constructs—such as virtual segmentation, policy-driven routing, and programmable firewalls—form the foundation for enforcing confidentiality, integrity, and availability across dynamic infrastructures. Effective network security design in the cloud requires not only technical precision but also strategic alignment with compliance frameworks, business continuity objectives, and evolving threat models.

Virtual Networking Foundations and Isolation Models

Cloud network security begins with an architectural shift from traditional, hardware-defined perimeter models to software-defined virtual networking constructs. At the core of this shift are Virtual Private Clouds (VPCs) and Virtual Networks (VNets), which serve as logical, isolated slices of the provider’s infrastructure. These constructs are not merely organizational tools—they define the boundaries for routing, control plane operations, and interconnectivity between cloud resources. Each VPC or VNet provides a controlled environment with configurable IP ranges, subnets, route tables, and associated access controls. These elements collectively form the ...