Subnet delegation gives explicit permissions to the service to create service-specific resources in the subnet using a unique identifier when deploying the service. This article describes how to add or remove a delegated subnet for an Azure service.
If you didn't create the subnet you would like to delegate to an Azure service, you need the following permission: Microsoft.Network/virtualNetworks/subnets/write. The built-in Network Contributor role also contains the necessary permissions.
If you didn't create the subnet you would like to delegate to an Azure service, you need the following permission: Microsoft.Network/virtualNetworks/subnets/write. The built-in Network Contributor role also contains the necessary permissions.
Azure PowerShell installed locally.
Sign in to Azure PowerShell and ensure you've selected the subscription with which you want to use this feature. For more information, see Sign in with Azure PowerShell.
Ensure your Az.Network module is 4.3.0 or later. To verify the installed module, use the command Get-InstalledModule -Name "Az.Network". If the module requires an update, use the command Update-Module -Name Az.Network if necessary.
This article requires the Azure PowerShell module version 5.4.1 or later. Run Get-Module -ListAvailable Az to find the installed version. If you need to upgrade, see Install Azure PowerShell module. If you're running PowerShell locally, you also need to run Connect-AzAccount -Environment AzureChinaCloud to create a connection with Azure.
If you didn't create the subnet you would like to delegate to an Azure service, you need the following permission: Microsoft.Network/virtualNetworks/subnets/write. The built-in Network Contributor role also contains the necessary permissions.
If you prefer to run CLI reference commands locally, install the Azure CLI. If you're running on Windows or macOS, consider running Azure CLI in a Docker container. For more information, see How to run the Azure CLI in a Docker container.
If you're using a local installation, sign in to the Azure CLI by using the az login command. To finish the authentication process, follow the steps displayed in your terminal. For other sign-in options, see Sign in with the Azure CLI.
When you're prompted, install the Azure CLI extension on first use. For more information about extensions, see Use extensions with the Azure CLI.
Run az version to find the version and dependent libraries that are installed. To upgrade to the latest version, run az upgrade.
This how-to article requires version 2.31.0 or later of the Azure CLI.
Create the virtual network
In this section, you create a virtual network and the subnet that you delegate to an Azure service.
In the search box at the top of the portal, enter Virtual network. Select Virtual networks in the search results.
Select vnet-1.
Select Subnets in Settings.
Select subnet-1.
Enter or select the following information:
Setting
Value
SUBNET DELEGATION
Delegate subnet to a service
Select the service that you want to delegate the subnet to. For example, Microsoft.Sql/managedInstances.
Select Save.
Use Add-AzDelegation to update the subnet named subnet-1 with a delegation named myDelegation to an Azure service. In this example Microsoft.Sql/managedInstances is used for the example delegation:
ProvisioningState : Succeeded
ServiceName : Microsoft.Sql/managedInstances
Actions : {Microsoft.Network/virtualNetworks/subnets/join/action}
Name : myDelegation
Etag : W/"9cba4b0e-2ceb-444b-b553-454f8da07d8a"
Id : /subscriptions/3bf09329-ca61-4fee-88cb-7e30b9ee305b/resourceGroups/test-rg/providers/Microsoft.Network/virtualNetworks/vnet-1/subnets/subnet-1/delegations/myDelegation
Use az network virtual network subnet update to update the subnet named subnet-1 with a delegation to an Azure service. In this example Microsoft.Sql/managedInstances is used for the example delegation: