A physical information technology (IT) infrastructure has its limitations. It is not flexible for dynamically allocating network resources to meet computing requirements. It is not easy to reconstruct a physical network structure. It is also expensive to construct a physical network. A virtualized IT infrastructure created with VMware is able to meet these challenges. The virtualized IT infrastructure is flexible. This chapter provides an overview about vCloud Networking and Security (vCNS). It illustrates how vCNS can be used to efficiently manage remote access, isolate users' networks from each other, and protect the private cloud. vCNS provides security shields to protect virtual machines and virtual networks. It centralizes the network and security management in a cloud environment. The chapter also introduces other vCNS components such as vShield App and vShield Endpoint. It presents an overview about vCNS implementation and provides detailed information about vShield Manager appliance deployment.