Integrate Azure Private Link with Your Virtual Network

Azure Private Link provides a secure and efficient way to access Azure PaaS services and customer-owned Azure resources over a private endpoint within your virtual network. This integration eliminates exposure to the public internet, enhancing your security posture.

Key Concepts

• Private Endpoint: A network interface that connects privately and securely to a service powered by Azure Private Link.
• Private Link Service: A new type of Azure Load Balancer frontend IP configuration that enables Private Link.
• Virtual Network (VNet): The fundamental building block for your private network in Azure.

Steps for Integration

1. Create a Private Endpoint

You'll need to create a private endpoint that points to your target Azure service (e.g., Azure SQL Database, Azure Storage Account, custom service). This is typically done through the Azure portal, Azure CLI, or PowerShell.

When creating a private endpoint, you'll specify:

• The subscription and resource group.
• The region.
• The name of the private endpoint.
• The target resource (the Azure service you want to connect to).
• The target sub-resource (e.g., sqlServer for Azure SQL Database).
• The virtual network and subnet where the private endpoint will reside.
• An option to integrate with Azure Private DNS Zone.

2. Configure DNS Resolution

Proper DNS resolution is crucial for accessing your service via the private endpoint. If you opted for private DNS zone integration, Azure handles this automatically. Otherwise, you'll need to manually create A records in your custom DNS server or Azure Private DNS Zone that point the service's FQDN to the private IP address of the private endpoint.

Example DNS configuration (manual):

Host Name: my-azure-sql.database.windows.net
Record Type: A
IP Address: <Private IP address of your private endpoint>
            

3. Accessing the Service from Your Virtual Network

Once the private endpoint is provisioned and DNS is configured, any resource within the same virtual network (or peered virtual networks, or networks connected via VPN/ExpressRoute) can access the target service using its original FQDN. The traffic will be routed privately through the private endpoint, bypassing the public internet.

4. Network Security Considerations

While Private Link secures the connection path, you should still implement appropriate network security measures:

• Network Security Groups (NSGs): Apply NSGs to the subnet containing your private endpoint to control inbound and outbound traffic.
• Azure Firewall: If you use Azure Firewall, configure rules to allow traffic to the private endpoint's IP address.
• Service-Specific Firewalls: Ensure any service-level firewalls (e.g., Azure SQL Database firewall) are configured to allow access from your virtual network's IP range or by specifically allowing Private Link connections.

Example Scenario: Connecting to Azure SQL Database

1. Create a Private Endpoint for your Azure SQL Database, targeting the sqlServer sub-resource.
2. Deploy the private endpoint to a subnet within your virtual network (e.g., 10.0.1.0/24).
3. Associate the private endpoint with an Azure Private DNS Zone for database.windows.net.
4. From a Virtual Machine within the same virtual network, you can now connect to your Azure SQL Database using its FQDN (e.g., my-azure-sql.database.windows.net). The connection will use the private IP address assigned to the private endpoint.

Troubleshooting

• DNS Resolution Issues: Verify your DNS configuration. Use nslookup or dig from a resource within your VNet to check if the FQDN resolves to the private IP.
• Connectivity Problems: Check NSG rules, Azure Firewall rules, and any service-level firewalls. Ensure the private endpoint's status in the Azure portal is 'Approved'.
• Service Availability: Confirm the target Azure service is running and accessible.

For more detailed information and advanced configurations, please refer to the official Azure Private Link documentation.