Delegate a subnet to Azure NetApp Files

You must delegate a subnet to Azure NetApp Files. When you create a volume, you need to specify the delegated subnet.


  • The wizard for creating a new subnet defaults to a /24 network mask, which provides for 251 available IP addresses. Using a /28 network mask, which provides for 11 usable IP addresses, is sufficient for most use cases. You should consider a larger subnet (for example, /26 network mask) in scenarios such as SAP HANA where many volumes and storage endpoints are anticipated. You can also stay with the default network mask /24 as proposed by the wizard if you don't need to reserve many client or VM IP addresses in your Azure Virtual Network (VNet). Note that the network mask of the delegated network cannot be changed after the initial creation.
  • In each VNet, only one subnet can be delegated to Azure NetApp Files.
    Azure enables you to create multiple delegated subnets in a VNet. However, any attempts to create a new volume will fail if you use more than one delegated subnet.
    You can have only a single delegated subnet in a VNet. A NetApp account can deploy volumes into multiple VNets, each having its own delegated subnet.
  • You cannot designate a network security group or service endpoint in the delegated subnet. Doing so causes the subnet delegation to fail.
  • Access to a volume from a globally peered virtual network is not currently supported using Basic networks features. Global VNet peering is supported with Standard network features. See Supported network topologies for more information.
  • For Azure NetApp Files support of User-defined routes (UDRs) and Network security groups (NSGs), see Constraints in Guidelines for Azure NetApp Files network planning.
    To establish routing or access control to the Azure NetApp Files delegated subnet, you can apply UDRs and NSGs to other subnets, even within the same VNet as the subnet delegated to Azure NetApp Files.


  1. Go to the Virtual networks blade in the Azure portal and select the virtual network that you want to use for Azure NetApp Files.

  2. Select Subnets from the Virtual network blade and click the +Subnet button.

  3. Create a new subnet to use for Azure NetApp Files by completing the following required fields in the Add Subnet page:

    • Name: Specify the subnet name.

    • Address range: Specify the IP address range.

    • Subnet delegation: Select Microsoft.NetApp/volumes.

      Subnet delegation

You can also create and delegate a subnet when you create a volume for Azure NetApp Files.

Next steps