Windows 10 Always On VPN and DirectAccess both provide seamless, transparent, always on remote network access for Windows clients. However, Always On VPN is provisioned to the user, not the machine as it is with DirectAccess. This presents a challenge for deployment scenarios that require the VPN connection to be established before the user logs on. For example, pre-logon connectivity is required to support remote logon without cached credentials. To address this issue and to provide feature parity with DirectAccess, Microsoft introduced support for a device tunnel configuration option beginning with Windows 10 version 1709 (Fall creators update).
Learn Windows 10 Always On VPN today! Register for an upcoming Always On VPN Hands-On Training class. More details here!
Prerequisites
To support an Always On VPN device tunnel, the client computer must be running Windows 10 Enterprise or Education version 1709 (Fall creators update) or later. It must also be domain-joined and have a computer certificate with the Client Authentication Enhanced Key Usage (EKU) issued by the organization’s Public Key Infrastructure (PKI).
In addition, only the built-in Windows VPN client is supported for Always On VPN device tunnel. Although Windows 10 Always On VPN user connections can be configured using various third-party VPN clients, they are not supported for use with the device tunnel.
VPN ProfileXML
The Always On VPN device tunnel is provisioned using an XML file. You can download a sample VPN ProfileXML file here. Make any changes required for your environment such as VPN server hostnames, routes, traffic filters, and remote address ranges. Optionally include the trusted network detection code, if required. Do not change the protocol type or authentication methods, as these are required.
Once the ProfileXML file is created, it can be deployed using Intune, System Center Configuration Manager (SCCM), or PowerShell. In this post I’ll cover how to configure Windows 10 Always On VPN device tunnel using PowerShell.
Client Configuration
Download the PowerShell script located here and then copy it to the target client computer. The Always On VPN device tunnel must be configured in the context of the local system account. To accomplish this, it will be necessary to use PsExec, one of the PsTools included in the Sysinternals suite of utilities. Download PsExec here, copy it to the target machine, and then run the following command in an elevated PowerShell command window.
PsExec.exe -i -s C:\windows\system32\WindowsPowerShell\v1.0\powershell.exe
Another elevated PowerShell window will open, this one now running in the context of the local system account. In this window, navigate to the folder where you copied the PowerShell script and XML file to. Run the PowerShell script and specify the name of the ProfileXML file, as shown below.
VPN_Profile_Device.ps1 -xmlFilePath .\profileXML_device.XML -ProfileName DeviceTunnel
To verify creation of the VPN device tunnel, run the following PowerShell command.
Get-VpnConnection -AllUserConnection
Note: In Windows 10 releases prior to 1903 the ConnectionStatus will always report Disconnected. This has been fixed in Windows 10 1903.
Server Configuration
If you are using Windows Server 2012 R2 or Windows Server 2016 Routing and Remote Access Service (RRAS) as your VPN server, you must enable machine certificate authentication for VPN connections and define a root certification authority for which incoming VPN connections will be authenticated with. To do this, open an elevated PowerShell command and run the following commands.
$VPNRootCertAuthority = “Common Name of trusted root certification authority”
$RootCACert = (Get-ChildItem -Path cert:LocalMachine\root | Where-Object {$_.Subject -Like “*$VPNRootCertAuthority*” })
Set-VpnAuthProtocol -UserAuthProtocolAccepted Certificate, EAP -RootCertificateNameToAccept $RootCACert -PassThru
Limitations
Using PowerShell to provision an Always On VPN device tunnel is helpful for initial testing and small pilot deployments, but it does not scale very well. For production deployments it is recommended that Microsoft Intune be used to deploy Always On VPN device tunnel.
Deploy Device Tunnel with Intune
Guidance for deploying an Always On VPN device tunnel using Microsoft Intune can be found here. You can also view the following demonstration video that includes detailed guidance for provisioning the Always On VPN device tunnel using Microsoft Intune.
Summary
Once the Always On VPN device tunnel is configured, the client computer will automatically establish the connection as soon as an active Internet connection is detected. This will enable remote logins for users without cached credentials, and allow administrators to remotely manage Always On VPN clients without requiring a user to be logged on at the time.
Additional Information
Deploy Windows 10 Always On VPN Device Tunnel using Microsoft Intune
VIDEO: Deploying Windows 10 Always On VPN Device Tunnel using Microsoft Intune
Windows 10 Always On VPN Device Tunnel Does Not Connect Automatically
Windows 10 Always On VPN Device Tunnel Does Not Appear in the UI
Windows 10 Always On VPN Hands-On Training
Windows 10 Always On VPN hands-on training classes now forming. Details 
Windows servers are required to implement DirectAccess. Always On VPN can be implemented using Windows servers as well, but it isn’t a hard requirement. Always On VPN is implemented entirely on the Windows 10 client, which means any third-party VPN device can be used on the back end, including Cisco, Checkpoint, Juniper, Palo Alto, Fortinet, SonicWALL, F5, strongSwan, and others! This provides tremendous deployment flexibility, making it possible to mix and match backend infrastructure if required. For example, a Windows RRAS VPN server with Palo Alto and SonicWALL firewalls could all be implemented at the same time (using the Windows built-in VPN client). Importantly, making changes to VPN infrastructure is much less impactful and disruptive to clients in the field. VPN devices can be upgraded, replaced, and moved internally without requiring corresponding policy changes on the client.
