Azure Private Link

Network Isolation

Private Link establishes private connectivity by creating a private endpoint in your virtual network. This endpoint is assigned an IP address from within your virtual network, ensuring that traffic to the service stays entirely within your private network space.

Key benefits:

• No public IP addresses are exposed for the service.
• Traffic does not traverse the public internet, reducing attack surface.
• Enhanced data exfiltration protection.

Access Control

Private Link offers granular control over who can access your services. You can manage access using:

• Network Security Groups (NSGs): Apply NSGs to the subnet containing your private endpoint to filter traffic.
• Azure Private DNS: Integrate with Azure Private DNS zones to map the service's fully qualified domain name (FQDN) to the private IP address of the private endpoint. This ensures that requests are resolved to the private IP within your network.
• Azure RBAC: Control who can create, manage, and approve private endpoints.

Example DNS configuration:

; In your Azure Private DNS Zone for 'privatelink.blob.core.windows.net'
@ IN A <private-endpoint-ip-address>
   IN AAAA <private-endpoint-ipv6-address> (if applicable)

Data Encryption

While Private Link itself doesn't encrypt data in transit between your VNet and the service endpoint (as it's already within the Azure backbone), it complements other Azure security measures:

• Transport Layer Security (TLS): Services accessible via Private Link typically use TLS for encrypting data in transit. Ensure TLS is enabled on the service itself.
• Encryption at Rest: Azure services provide options for encrypting data at rest using platform-managed keys or customer-managed keys.

Simplified Network Management

Private Link simplifies network architecture by removing the need for complex VNet peering, VPN gateways, or ExpressRoute circuits solely for accessing PaaS services. This reduces operational overhead and potential security misconfigurations.

Endpoint Policies

For services like Azure Storage and Azure SQL Database, you can define endpoint network policies. These policies allow you to restrict which storage accounts or SQL servers a private endpoint can connect to, adding another layer of security.