Secure your Origin with Private Link in Azure Front Door Premium

Azure Private Link enables you to access Azure PaaS services and services hosted in Azure over a private endpoint in your virtual network. Traffic between your virtual network and the service goes over the Microsoft backbone network, eliminating exposure to the public Internet.

Azure Front Door Premium can connect to your origin using Private Link. Your origin can be hosted in a virtual network or hosted as a PaaS service such as Azure App Service or Azure Storage. Private Link removes the need for your origin to be accessed publicly.

Diagram of Azure Front Door with Private Link enabled.

When you enable Private Link to your origin in Azure Front Door Premium, Front Door creates a private endpoint on your behalf from an Azure Front Door managed regional private network. You'll receive an Azure Front Door private endpoint request at the origin pending your approval.

Important

You must approve the private endpoint connection before traffic can pass to the origin privately. You can approve private endpoint connections by using the Azure portal, Azure CLI, or Azure PowerShell. For more information, see Manage a Private Endpoint connection.

After you enable an origin for Private Link and approve the private endpoint connection, it can take a few minutes for the connection to be established. During this time, requests to the origin will receive an Azure Front Door error message. The error message will go away once the connection is established.

Once your request is approved, a private IP address gets assigned from the Azure Front Door managed virtual network. Traffic between your Azure Front Door and your origin will communicate using the established private link over the Microsoft backbone network. Incoming traffic to your origin is now secured when arriving at your Azure Front Door.

Screenshot of enable Private Link service checkbox from origin configuration page.

Association of a private endpoint with an Azure Front Door profile

Private endpoint creation

Within a single Azure Front Door profile, if two or more Private Link enabled origins are created with the same set of Private Link, resource ID and group ID, then for all such origins only one private endpoint gets created. Connections to the backend can be enabled using this private endpoint. This setup means you only have to approve the private endpoint once because only one private endpoint gets created. If you create more Private Link enabled origins using the same set of Private Link location, resource ID and group ID, you won't need to approve anymore private endpoints.

Single private endpoint

For example, a single private endpoint gets created for all the different origins across different origin groups but in the same Azure Front Door profile as shown in the below table:

Diagram showing a single private endpoint created for origins created in the same Azure Front Door profile.

Multiple private endpoints

A new private endpoint gets created in the following scenario:

  • If the region, resource ID or group ID changes:

    Diagram showing a multiple private endpoint created because changes in the region and resource ID for the origin.

    Note

    The Private Link location and the hostname has changed, resulting in extra private endpoints created and requires approval for each one.

  • When the Azure Front Door profile changes:

    Diagram showing a multiple private endpoint created because the origin is associated with multiple Azure Front Door profiles.

    Note

    Enabling Private Link for origins in different Front Door profiles will create extra private endpoints and requires approval for each one.

Private endpoint removal

When an Azure Front Door profile gets deleted, private endpoints associated with the profile will also get deleted.

Single private endpoint

If AFD-Profile-1 gets deleted, then the PE1 private endpoint across all the origins will also be deleted.

Diagram showing if AFD-Profile-1 gets deleted then PE1 across all origins will get deleted.

Multiple private endpoints

  • If AFD-Profile-1 gets deleted, all private endpoints from PE1 through to PE4 will be deleted.

    Diagram showing if AFD-Profile-1 gets deleted, all private endpoints from PE1 through PE4 gets deleted.

  • Deleting a Front Door profile won't affect private endpoints created for a different Front Door profile.

    Diagram showing Azure Front Door profile getting deleted won't affect private endpoints in other Front Door profiles.

    For example:

    • If AFD-Profile-2 gets deleted, only PE5 will be removed.
    • If AFD-Profile-3 gets deleted, only PE6 will be removed.
    • If AFD-Profile-4 gets deleted, only PE7 will be removed.
    • If AFD-Profile-5 gets deleted, only PE8 will be removed.

Region availability

Azure Front Door private link is available in the following regions:

Americas Europe Africa Asia Pacific
Brazil South France Central South Africa North Australia East
Canada Central Germany West Central Central India
Central US North Europe Japan East
East US Norway East Korea Central
East US 2 UK South East Asia
South Central US West Europe
West US 3 Sweden Central

Limitations

Origin support for direct private endpoint connectivity is currently limited to:

  • Storage (Azure Blobs)
  • App Services
  • Internal load balancers.

The Azure Front Door Private Link feature is region agnostic but for the best latency, you should always pick an Azure region closest to your origin when choosing to enable Azure Front Door Private Link endpoint.

Next steps