Azure Private Link and Private Endpoint Overview

Introduction

Azure Private Link provides the ability to access Azure Platform as a Service (PaaS) and Azure hosted customer-owned services over a private endpoint in your virtual network. Traffic between your virtual network and the service travels the Microsoft backbone network, eliminating exposure to the public internet.

This document provides an overview of Azure Private Link and private endpoints, explaining their purpose, functionality, and benefits.

What is Azure Private Link?

Azure Private Link is a service that offers a private connection from your virtual network to Azure services that are hosted on Azure infrastructure. It simplifies network connectivity and security by enabling you to connect to Azure PaaS services (like Azure Storage, Azure SQL Database, Azure Cosmos DB) and Azure hosted customer-owned services from your virtual network using private IP addresses.

With Private Link, you no longer need to:

• Expose Azure services to the public internet.
• Use Network Security Groups (NSGs) or Azure Firewall to manage traffic to Azure services.
• Set up complex VPN or ExpressRoute circuits for private access to Azure services.

What is an Azure Private Endpoint?

An Azure Private Endpoint is a network interface that connects you privately and securely to a service powered by Azure Private Link. It enables you to send and receive data from that Azure service using a private IP address from your virtual network, effectively bringing the service into your network.

Key characteristics of a private endpoint:

• It resides within a specific subnet of your virtual network.
• It gets assigned a private IP address from your virtual network's address space.
• It allows secure access to Azure services without traversing the public internet.

How It Works

Azure Private Link works by leveraging Network as a Service (NaaS). When you create a private endpoint for a specific Azure service:

1. A network interface is provisioned in your virtual network.
2. This interface is assigned a private IP address from the subnet you select.
3. Azure DNS is used to map the service's public endpoint to the private IP address of your private endpoint within your virtual network.
4. When your application or resource attempts to connect to the Azure service using its standard FQDN (Fully Qualified Domain Name), the DNS resolution within your virtual network will point to the private IP address.
5. All traffic then flows securely over the Microsoft backbone network directly to the Azure service.

Key Benefits

• Enhanced Security: Traffic stays on the Microsoft backbone, never traversing the public internet, which significantly reduces exposure to threats.
• Reduced Network Complexity: Eliminates the need for complex network configurations like VPNs or ExpressRoute circuits solely for accessing Azure services.
• Compliance: Helps meet strict security and compliance requirements by isolating sensitive data and services.
• Consistent Networking Experience: Provides a consistent way to access Azure PaaS services and your own services hosted in Azure.
• Private Access to Your Own Services: Private Link also allows you to expose your own services (e.g., in AKS, on-premises) to other virtual networks in a private manner.

Common Use Cases

Azure Private Link is ideal for scenarios where data exfiltration protection and secure, private access are paramount:

• Accessing Azure Storage accounts without public IP exposure.
• Connecting securely to Azure SQL Database or Azure Cosmos DB from your virtual network.
• Enabling private connectivity to Azure Key Vault for managing secrets.
• Securing access to Azure Databricks or Azure Synapse Analytics.
• Providing private access to your own custom applications hosted in Azure Kubernetes Service (AKS) or Azure App Service.
• Connecting to on-premises applications securely via Azure.

Getting Started

To get started with Azure Private Link and private endpoints:

1. Identify the Azure service you want to connect to privately.
2. Ensure the service supports Private Link (most modern Azure services do).
3. Create a private endpoint in your target virtual network, selecting the appropriate subnet.
4. Configure DNS settings to ensure your virtual network resolves the service FQDN to the private IP address of the private endpoint.

Refer to the Azure Private Link documentation for detailed step-by-step guides and service-specific configurations.