Windows activation fails in forced tunneling scenario

Applies to: ✔️ Windows VMs

This article describes how to resolve the KMS activation problem that you might experience when you enable forced tunneling in site-to-site VPN connection or ExpressRoute scenarios.

Symptom

You enable forced tunneling on Azure virtual network subnets to direct all Internet-bound traffic back to your on-premises network. In this scenario, the Azure virtual machines (VMs) that run Windows fail to activate Windows.

Cause

The Azure Windows VMs need to connect to the Azure KMS server for Windows activation. The activation requires that the activation request come from an Azure public IP address. In the forced tunneling scenario, the activation fails because the activation request comes from your on-premises network instead of from an Azure public IP address.

Solution

To resolve this problem, use the Azure custom route to route activation traffic to the Azure KMS server.

The first DNS name of the KMS server for the Azure Global cloud is azkms.core.windows.net with two IP addresses: 20.118.99.224 and 40.83.235.53. The second DNS name of the KMS server for the Azure Global cloud is kms.core.windows.net with an IP address of 23.102.135.246. If you use other Azure platforms such as Azure Germany, you must use the IP address of the corresponding KMS server. For more information, see the following table:

To add the custom route, follow these steps:

For Resource Manager VMs

1. Open Azure PowerShell, and then sign in to your Azure subscription.

2. Run the following commands:

   # First, get the virtual network that hosts the VMs that have activation problems. In this case, we get virtual network ArmVNet-DM in Resource Group ArmVNet-DM:
   $vnet = Get-AzVirtualNetwork -ResourceGroupName "ArmVNet-DM" -Name "ArmVNet-DM"
   
   # Next, create a route table:
   $RouteTable = New-AzRouteTable -Name "ArmVNet-DM-KmsDirectRoute" -ResourceGroupName "ArmVNet-DM" -Location "centralus"
   
   # Next, configure the route table:
   Add-AzRouteConfig -Name "DirectRouteToKMS" -AddressPrefix 23.102.135.246/32 -NextHopType Internet -RouteTable $RouteTable
   Add-AzRouteConfig -Name "DirectRouteToAZKMS01" -AddressPrefix 20.118.99.224/32 -NextHopType Internet -RouteTable $RouteTable
   Add-AzRouteConfig -Name "DirectRouteToAZKMS02" -AddressPrefix 40.83.235.53/32 -NextHopType Internet -RouteTable $RouteTable
   
   Set-AzRouteTable -RouteTable $RouteTable
   
   # Next, attach the route table to the subnet that hosts the VMs:
   Set-AzVirtualNetworkSubnetConfig -Name "Subnet01" -VirtualNetwork $vnet -AddressPrefix "10.0.0.0/24" -RouteTable $RouteTable
   
   Set-AzVirtualNetwork -VirtualNetwork $vnet
   

3. Go to the VM that has activation problems. Use PsPing to test if it can reach the KMS server:

   psping kms.core.windows.net:1688
   psping azkms.core.windows.net:1688
   

4. Try to activate Windows, and see if the problem is resolved.

Next steps

• KMS Client Setup Keys
• Review and Select Activation Methods

Contact us for help

If you have questions or need help, create a support request, or ask Azure community support. You can also submit product feedback to Azure feedback community.