An organization is deploying a multi-tier business application consisting of several virtual machines and database backend services in Microsoft Azure. The security team requires that all compute instances reside within an isolated private network, communicate securely with one another using private IP addresses, and remain restricted from direct public internet exposure by default. Which Azure service or component should the organization deploy to meet these requirements?

Azure Virtual Network (VNet): ### What Azure Virtual Network (VNet) is An **Azure Virtual Network (VNet)** is the fundamental building block for private networks in Microsoft Azure. It is a logically isolated network hosted within the Azure cloud that represents an organization's own private network environment. VNets allow many types of Azure resources, such as **Azure Virtual Machines (VMs)**, to securely communicate with each other, the internet, and on-premises networks. ### How it meets the requirements - **Network isolation**: VNets provide complete logical isolation from other tenants and workloads in Azure, ensuring dedicated address space management. - **Private IP communication**: Resources connected to the same VNet can communicate directly with one another using assigned **private IP addresses** without traversing the public internet. - **Access control and security**: VNets allow administrators to segment resources into **subnets** and apply **Network Security Groups (NSGs)** to strictly control inbound and outbound traffic. ### Key advantages and capabilities - **Subnet segmentation**: Divides the VNet IP address range into smaller subnets to organize application tiers (e.g., web, application, and database tiers). - **Secure default posture**: Keeps internal traffic private and enables filtering of unauthorized external internet traffic. - **Service endpoints and private endpoints**: Connects Azure PaaS resources securely into the virtual network address space. - **Hybrid connectivity support**: Connects seamlessly to on-premises data centers via **Azure VPN Gateway** or **Azure ExpressRoute**. ### Why this is optimal Deploying an **Azure Virtual Network** is the foundational requirement for establishing private IP communication and network-level security boundaries in Azure IaaS and PaaS architectures.

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