Azure Virtual WAN Private Link: How-To Guide

Introduction to Azure Virtual WAN Private Link

Azure Virtual WAN provides optimized and automated branch connectivity to Azure and to sites worldwide. Integrating Azure Private Link with Virtual WAN enables you to securely connect to Azure Platform-as-a-Service (PaaS) services using private endpoints. This eliminates the need for public internet exposure, enhancing your security posture and simplifying network management.

This guide will walk you through the process of setting up and utilizing Azure Private Link within your Virtual WAN environment.

Overview: How it Works

Azure Private Link allows you to provision a private endpoint in your Virtual WAN's virtual network. This private endpoint connects to a specific Azure PaaS service (e.g., Azure Storage, Azure SQL Database). Traffic destined for that service from within your Virtual WAN will then be routed directly over the Microsoft backbone network, bypassing the public internet.

Key components involved:

Azure Virtual WAN: The central hub for your global network.
Virtual Network (VNet): Where your private endpoint will reside. This VNet is typically connected to your Virtual WAN hub.
Private Endpoint: A network interface that connects your VNet privately to an Azure service.
Azure PaaS Service: The service you want to access privately (e.g., Azure Cosmos DB, Azure Key Vault).

Key Benefits

Enhanced Security: Traffic stays within the Azure network, reducing exposure to threats.
Simplified Network Architecture: Eliminates the need for complex NAT configurations or VPNs to access PaaS services.
Consistent Connectivity: Provides a unified networking experience across your Azure and on-premises resources.
Scalability: Leverages Azure's robust and scalable network infrastructure.
Improved Performance: Reduced latency and increased throughput by using the Microsoft backbone.

Common Use Cases

Securely accessing Azure Storage accounts from branch offices or VNet-connected on-premises networks.
Connecting to Azure SQL Databases or Azure Cosmos DB without exposing them to the public internet.
Enabling private access to Azure Key Vault for secrets management.
Integrating Azure PaaS services into a hub-and-spoke topology managed by Virtual WAN.

How-To Steps

Follow these steps to implement Azure Private Link with Azure Virtual WAN:

Step 1: Prerequisites

Ensure you have the following:

An active Azure subscription.
A configured Azure Virtual WAN with at least one hub.
A Virtual Network (VNet) connected to your Virtual WAN hub.
The specific Azure PaaS service you want to access privately deployed and configured.

Step 2: Create a Private Endpoint

You can create a private endpoint using the Azure portal, Azure CLI, or Azure PowerShell.

Using Azure Portal:

Navigate to the Azure portal.
Search for "Private endpoint" and select it.
Click "Create".
Select your Subscription, Resource group, and Name for the private endpoint.
For "Region", select the region where your Virtual Network resides.
Under "Resource", select the specific Azure PaaS service you want to connect to. You may need to select the resource type and then the specific instance.
Under "Virtual network", select the VNet connected to your Virtual WAN hub.
Optionally, configure a private DNS zone. This is highly recommended for seamless name resolution.
Review and create the private endpoint.

Using Azure CLI:


az network private-endpoint create \
  --name <private-endpoint-name> \
  --resource-group <resource-group-name> \
  --location <region> \
  --vnet-name <vnet-name> \
  --subnet <subnet-name> \
  --private-connection-resource-id "<resource-id-of-azure-paas-service>" \
  --group-id <group-id-of-azure-paas-service> \
  --connection-name <connection-name>

Replace placeholders with your specific details. The --group-id varies per service (e.g., 'blob' for Storage, 'sql' for SQL Database).

Step 3: Configure DNS

To ensure seamless access, configure DNS resolution for your private endpoint.

Using Private DNS Zones: When creating the private endpoint, you can associate it with a private DNS zone. Azure will automatically create the necessary A records. Ensure your VNet is linked to this private DNS zone.
Manual DNS Configuration: If not using automatic association, you'll need to manually create an A record in your DNS server (e.g., Azure DNS private zone) that maps the private endpoint's FQDN (e.g., privatelink.blob.core.windows.net) to its private IP address.

Refer to Azure Private Link documentation for specific DNS configurations per service.

Step 4: Verify Connectivity

Once the private endpoint is provisioned and DNS is configured, test connectivity:

From a VM or resource within the VNet connected to your Virtual WAN hub, attempt to access the Azure PaaS service using its private endpoint.
For example, if connecting to Azure Storage, try mounting the storage account or accessing blobs via its private IP or FQDN.
You can use tools like ping or nslookup to verify name resolution and connectivity to the private IP address.

Conclusion

Azure Virtual WAN combined with Azure Private Link offers a robust and secure method for accessing Azure PaaS services. By keeping traffic within the Azure backbone, you significantly enhance your security posture and simplify your network management. Implementing these steps will help you leverage the full potential of private connectivity within your Azure environment.

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