Virtual Network Private Endpoints

Introduction to Private Endpoints

Azure Private Endpoint is a network interface that connects you privately and securely to a service powered by Azure Private Link. Private Endpoint uses a private IP address from your virtual network, effectively bringing the Azure service into your virtual network. This enables you to access the service as if it were deployed in your own network, with all traffic flowing through your virtual network. This greatly enhances security by eliminating exposure to the public internet.

How Private Endpoints Work

When you create a private endpoint for an Azure service, it's assigned a private IP address in your virtual network. A network security group (NSG) associated with this private endpoint can be configured to filter traffic. The service itself isn't modified, but connectivity is routed through the private endpoint. This means:

• Data travels across the Microsoft backbone network, not the public internet.
• You can restrict network access to the Azure service by disabling public network access on the service itself.
• You can use private IP addresses to access the service within your virtual network.

Benefits of Using Private Endpoints

• Enhanced Security: Reduces attack surface by removing public internet exposure.
• Simplified Network Architecture: Integrates Azure PaaS services seamlessly into your virtual network.
• Compliance: Helps meet stringent data exfiltration and regulatory requirements.
• Consistent Management: Manage access to PaaS services using familiar virtual network security controls.

Common Use Cases

Private endpoints are ideal for a variety of scenarios, including:

• Securely accessing Azure SQL Database or Azure Synapse Analytics from an on-premises network via Azure ExpressRoute or VPN.
• Connecting Azure services like Azure Storage or Azure Key Vault to applications deployed in an Azure virtual network without exposing them publicly.
• Implementing a secure multi-tier application architecture where backend services are only accessible privately.

Configuring a Private Endpoint

The configuration process typically involves the following steps:

1. Navigate to the Azure service you want to connect to.
2. In the service's menu, select "Private endpoint connections" under the "Security" or "Networking" section.
3. Click "+ Private endpoint".
4. Provide details such as your subscription, resource group, region, and a name for the private endpoint.
5. Select the target Azure service and its specific sub-resource (e.g., blob, queue for Storage).
6. Choose your virtual network and subnet.
7. You can opt to integrate with Azure DNS for private IP resolution or use your own DNS solution.
8. Review and create the private endpoint.

Example using Azure CLI

az network private-endpoint create \
    --name myPrivateEndpoint \
    --resource-group myResourceGroup \
    --vnet-name myVNet \
    --subnet mySubnet \
    --prod \
    --group-ids myResourceProvider \
    --private-connection-resource-id "/subscriptions/00000000-0000-0000-0000-000000000000/resourceGroups/myResourceGroup/providers/Microsoft.Storage/storageAccounts/mystorageaccount" \
    --location eastus
                    

DNS Considerations

Proper DNS resolution is crucial for private endpoints. When using Azure Private DNS Zones, the private endpoint automatically creates an A record pointing to its private IP address. For custom DNS solutions, you need to manually create conditional forwarders or A records to resolve the service's FQDN to the private IP address of the private endpoint.

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