Azure Private Link for Virtual Networks
Azure Private Link enables you to access Azure Platform as a Service (PaaS) and Azure-hosted customer-owned/partner 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.
What is Azure Private Link?
Azure Private Link simplifies network connectivity for Azure services. It provides a private IP address from your virtual network, effectively bringing the service into your private network. You can use private endpoints to connect your virtual machines to services like Azure Storage, Azure SQL Database, and Azure Key Vault, or even to your own services hosted in Azure or on-premises.
Benefits of Private Link
- Enhanced Security: Data doesn't traverse the public internet, reducing the attack surface.
- Simplified Network Architecture: Eliminates the need for complex network configurations like NAT gateways or complex firewall rules for accessing PaaS services.
- Consistent Connectivity: Provides a consistent experience for accessing Azure services and your own services across Azure and on-premises.
- Compliance: Helps meet stringent compliance and regulatory requirements by keeping data within your private network.
Key Components
- Private Endpoint: A network interface that connects privately and securely to a service. It's assigned a private IP address from your virtual network.
- Private Link Service: A service that you create in your virtual network to expose your own Azure services (e.g., applications running on VMs, AKS, or App Service Environments) to consumers via Private Link.
- Network Security Groups (NSGs): Can be applied to the subnet where the private endpoint resides to further control traffic.
How it Works
When you create a private endpoint for a supported Azure service, a network interface is created in your virtual network. This interface is assigned a private IP address from your virtual network's address space. When you send traffic to the service, it's routed directly to the private endpoint, ensuring it stays within your virtual network and the Microsoft backbone.
Example Scenario: Accessing Azure SQL Database
Traditionally, you would connect to Azure SQL Database using its public endpoint, which might require opening firewall rules on your virtual network. With Private Link, you create a private endpoint for your Azure SQL Database. This endpoint gets a private IP address in your virtual network. Now, your applications within that virtual network can connect to the database using this private IP address, without ever going over the public internet.
Configuring Private Endpoints
You can configure private endpoints through the Azure portal, Azure CLI, Azure PowerShell, or ARM templates.
Using Azure CLI:
az network private-endpoint create \
--resource-group MyResourceGroup \
--name MyPrivateEndpoint \
--vnet-name MyVNet \
--subnet MySubnet \
--private-connection-resource-id "/subscriptions/{subscriptionId}/resourceGroups/MyResourceGroup/providers/Microsoft.Sql/servers/MySqlServer" \
--group-ids "sqlServer" \
--location "West US"
Private Link Service
Private Link Service enables you to create your own private link service. This allows consumers to connect to your services (e.g., applications running on Azure) using private endpoints from their virtual networks.
Use Cases for Private Link Service:
- Exposing multi-tenant SaaS applications securely.
- Providing secure access to internal line-of-business applications hosted on Azure.
- Enabling secure data exchange with partners.