Always On VPN with Azure Gateway

Always On VPN with Azure GatewayRecently I wrote about VPN server deployment options for Windows 10 Always On VPN in Azure. In that post I indicated the native Azure VPN gateway could be used to support Always On VPN connections using Internet Key Exchange version 2 (IKEv2) and Secure Socket Tunneling Protocol (SSTP). In this post I’ll outline the requirements and configuration steps for implementing this solution.

Requirements

To support Always On VPN, point-to-site VPN connections must be enabled on the Azure VPN gateway. Not all Azure VPN gateways are alike, and point-to-site connections are not supported in all scenarios. For Always On VPN, the Azure VPN gateway must meet the following requirements.

VPN SKU

The Azure VPN gateway SKU must be VpnGw1, VpnGw2, VpnGw3, VpnGw1AZ, VpnGw2AZ, or VpnGw3AZ. The Basic SKU is not supported.

VPN Type

The VPN type must be route-based. Policy-based VPN gateways are not supported for point-to-site VPN connections.

Limitations

Using the Azure VPN gateway for Always On VPN may not be ideal in all scenarios. The following limitations should be considered thoroughly before choosing the Azure VPN gateway for Always On VPN.

Device Tunnel

RADIUS/EAP authentication for user tunnel connections is not supported if the Azure VPN gateway is configured to support device tunnel with machine certificate authentication.

Maximum Connections

A maximum of 250, 500, and 1000 concurrent IKEv2 connections are supported when using the VpnGw1/AZ, VpnGw2/AZ, and VpnGw3/AZ SKUs, respectively (x2 for active/active gateway deployments). In addition, a maximum of 128 concurrent SSTP connections are supported for all VPN gateway SKUs (x2 for active/active gateway deployments).

Always On VPN with Azure Gateway

Reference: https://docs.microsoft.com/en-us/azure/vpn-gateway/vpn-gateway-about-vpngateways#gwsku

RADIUS Requirements

To support Always On VPN connections, the Azure VPN gateway must be configured to authenticate to a RADIUS server. The RADIUS server must be reachable from the VPN gateway subnet. The RADIUS server can be hosted in Azure or on-premises. Before proceeding, ensure that any network routes, firewall rules, and site-to-site VPN tunnel configuration is in place to allow this communication.

RADIUS Configuration

Guidance for configuring Windows Server NPS for Always On VPN can be found here. The only difference when configuring NPS for use with Azure VPN gateway is the RADIUS client configuration.

Open the NPS management console (nps.msc) and follow the steps below to configure Windows Server NPS to support Always On VPN client connections from the Azure VPN gateway.

1. Expand RADIUS Clients and Servers.
2. Right-click RADIUS Clients and choose New.
3. Enter a descriptive name in the Friendly name field.
4. Enter the Azure VPN gateway subnet using CIDR notation in the Address (IP or DNS) field. The gateway subnet can be found by viewing the properties of the Azure VPN gateway in the Azure portal.
5. Enter the shared secret to be used for RADIUS communication in the Shared secret field.

Always On VPN with Azure Gateway

Azure VPN Gateway Configuration

To begin, provision a Virtual Network Gateway in Azure that meets the requirements outlined above. Guidance for implementing an Azure VPN gateway can be found here. Once complete, follow the steps below to enable support for Always On VPN client connections.

Enable Point-to-Site

Perform the following steps to enable point-to-site VPN connectivity.

1. In the navigation pane of the Azure VPN gateway settings click Point-to-site configuration.
2. Click Configure Now and specify an IPv4 address pool to be assigned to VPN clients. This IP address pool must be unique in the organization and must not overlap with any IP address ranges defined in the Azure virtual network.
3. From the Tunnel type drop-down list select IKEv2 and SSTP (SSL).
4. In the RADIUS authentication field enter the IPv4 address of the RADIUS server. At the time of this writing only a single IPv4 address is supported. If RADIUS redundancy is required, consider creating a load balanced NPS cluster.
5. In the Server secret field enter the RADIUS shared secret.
6. Click Save to save the configuration.

Always On VPN with Azure Gateway

VPN Client Configuration

Perform the following steps to configure a Windows 10 VPN client to connect to the Azure VPN gateway.

Download VPN Configuration

1. Click Point-to-site configuration.
2. Click Download VPN client.
3. Select EAPMSCHAv2 (yes, that’s correct even if EAP-TLS will be used!)
4. Click Download.
5. Open the downloaded zip file and extract the VpnSettings.XML file from the Generic folder.
6. Copy the FQDN in the VpnServer element in VpnSettings.XML. This is the FQDN that will be used in the template VPN connection and later in ProfileXML.

Always On VPN with Azure Gateway

Create a Test VPN Connection

On a Windows 10 device create a test VPN profile using the VPN server address copied previously. Configure EAP settings to match those configured on the NPS server and test connectivity.

Create an Always On VPN Connection

Once the VPN has been validated using the test profile created previously, the VPN server and EAP configuration from the test profile can be used to create the Always On VPN profile for publishing using Intune, SCCM, or PowerShell.

IKEv2 Security Configuration

The default IKEv2 security parameters used by the Azure VPN gateway are better than Windows Server, but the administrator will notice that a weak DH key (1024 bit) is used in phase 1 negotiation.

Always On VPN with Azure Gateway

Use the following PowerShell commands to update the default IKEv2 security parameters to recommended baseline defaults, including 2048-bit keys (DH group 14) and AES-128 for improved performance.

Connect-AzAccount
Select-AzSubscription -SubscriptionName [Azure Subscription Name]

$Gateway = [Gateway Name]
$ResourceGroup = [Resource Group Name]

$IPsecPolicy = New-AzVpnClientIpsecParameter -IpsecEncryption AES128 -IpsecIntegrity SHA256 -SALifeTime 28800 -SADataSize 102400000 -IkeEncryption AES128 -IkeIntegrity SHA256 -DhGroup DHGroup14 -PfsGroup PFS14

Set-AzVpnClientIpsecParameter -VirtualNetworkGatewayName $Gateway -ResourceGroupName $ResourceGroup -VpnClientIPsecParameter $IPsecPolicy

Note: Be sure to update the cryptography settings on the test VPN connection and in ProfileXML for Always On VPN connections to match the new VPN gateway settings. Failing to do so will result in an IPsec policy mismatch error.

Additional Information

Microsoft Azure VPN Gateway Overview

About Microsoft Azure Point-to-Site VPN

Windows 10 Always On VPN IKEv2 Security Configuration

 

 

 

Always On VPN Device Tunnel Does Not Connect Automatically

When configuring a Windows 10 Always On VPN device tunnel, the administrator may encounter a scenario in which the device tunnel does not connect automatically. This can occur even when ProfileXML is configured with the AlwaysOn element set to “true”.

Always On VPN Device Tunnel Does Not Connect Automatically

Manual Connection

An administrator can establish a device tunnel connection manually using rasdial.exe however, indicating no issues with connectivity or authentication that would prevent a successful automatic connection.

Always On VPN Device Tunnel Does Not Connect Automatically

Root Cause

This scenario will occur when the device tunnel configuration is applied to a Windows 10 Professional edition client.

Always On VPN Device Tunnel Does Not Connect Automatically

Device Tunnel Support

The Windows 10 Always On VPN device tunnel is supported only on Windows 10 1709 or later Enterprise edition clients that are domain-joined. To ensure the device tunnel connects automatically, upgrade to Windows 10 Enterprise 1709 or later and join it to a domain.

Always On VPN Device Tunnel Does Not Connect Automatically

Source: https://docs.microsoft.com/en-us/windows-server/remote/remote-access/vpn/vpn-device-tunnel-config#device-tunnel-requirements-and-features

Additional Information

Windows 10 Always On VPN Device Tunnel Configuration using PowerShell

Windows 10 Always On VPN Device Tunnel Missing in the Windows UI

Deleting a Windows 10 Always On VPN Device Tunnel

Always On VPN IKEv2 and SSTP Fallback

Always On VPN IKEv2 and SSTP FallbackA while back I wrote about the various VPN protocols supported for Windows 10 Always On VPN. The two most common are Internet Key Exchange version 2 (IKEv2) and Secure Socket Tunneling Protocol (SSTP). The article covers in detail each protocol’s advantages and disadvantages. To summarize, IKEv2 provides the best security (when configured correctly!) and SSTP is firewall-friendly ensuring ubiquitous access. Ideally an Always On VPN connection will attempt to use the more secure IKEv2 first, then fallback to SSTP only when IKEv2 is unavailable. Unfortunately, Always On VPN connections do not work this way today.

IKEv2 and SSTP

IKEv2 and SSTP are not mutually exclusive. When using Windows Routing and Remote Access Service (RRAS) as the VPN server, both protocols can be configured and enabled for VPN clients. To allow VPN clients to automatically select a protocol, the NativeProtocolType element in ProfileXML can be set to Automatic.

Always On VPN IKEv2 and SSTP Fallback

IKEv2 with SSTP Fallback?

In theory, with the NativeProtocolType set to Automatic, the Windows 10 client would first attempt to establish an IKEv2 connection, then fall back to SSTP if IKEv2 is not available. In practice, this is not the case.

SSTP Preferred over IKEv2

In operation, setting the NativeProtocolType to Automatic results in the Windows 10 client attempting to establish a VPN connection using SSTP first! If the SSTP connection fails, only then will IKEv2 be used. The only scenario in which I can imagine SSTP failing and IKEv2 being successful would be if SSTP is not supported by the VPN server. Sadly, this scenario may result in failed connections due to a bug in the way ProfileXML settings are processed. Details here.

VPN Strategy

The initial VPN protocol selection behavior is dictated by the VpnStrategy setting of the Always On VPN connection in the rasphone.pbk file. This file can be found under C:\Users\[username]\AppData\Roaming\Microsoft\Network\Connections\Pbk. The documentation on the Microsoft website is terribly outdated and does not include the following important VpnStrategy settings pertinent to Windows 10 Always On VPN connections.

  • 5 = Only SSTP is attempted
  • 6 = SSTP is attempted first
  • 7 = Only IKEv2 is attempted
  • 8 = IKEv2 is attempted first
  • 14 = IKEv2 is attempted followed by SSTP

Always On VPN Default Behavior

For Always On VPN, when the NativeProtocolType is set to Automatic in ProfileXML, VpnStrategy is set to 6 by default, which means the connection will attempt to use SSTP first. If it fails, IKEv2 will be attempted.

Always On VPN IKEv2 and SSTP Fallback

If the NativeProtocolType in ProfileXML is set to IKEv2, VpnStrategy is set to 7 and only IKEv2 is used. A connection using SSTP is never attempted.

Workaround

Setting the VpnStrategy to 8 or 14 will force the client to attempt an IKEv2 connection first. However, this setting is dynamically updated by Windows and is subject to change. For example, if an IKEv2 connection fails and SSTP is successful, Windows will then set the VpnStrategy to 6 and all subsequent VPN connection attempts will use SSTP first. Because of this it will be necessary to update the VpnStrategy setting each time prior to establishing a VPN connection. This will require some clever scripting and perhaps automation using a scheduled task based on an event trigger. I will leave that custom configuration as an exercise for the reader. If you’ve developed something to address this challenge, please feel free to share in the comments below. 🙂

Additional Information

Always On VPN Protocol Recommendations for Windows Server RRAS

Always On VPN IKEv2 Security Configuration

Always On VPN Certificate Requirements for IKEv2

Always On VPN IKEv2 Load Balancing with KEMP LoadMaster Load Balancer

Always On VPN Hands-On Training Calendar for 2019

This year I’ll once again be bringing my popular Windows 10 Always On VPN hands-on training classes to various cities throughout the U.S. and Europe. These three-day training classes feature comprehensive, in-depth training for designing, implementing, and supporting an Always On VPN deployment in the enterprise. More details and a course syllabus can be found here.

The following dates and locations will be featured in 2019.

  • February 26-28, 2019 – Los Angeles or San Francisco, CA (location based on demand)
  • March 26-28, 2019 – Atlanta, GA
  • April 16-18, 2019 – Chicago, IL
  • May 21-23, 2019 – New York, NY
  • June 3-5, 2019 – Bern, Switzerland
    • Note: This session will be hosted by RealStuff. Class details and registration here.
  • September 10-12, 2019 – Dallas, TX
  • December 10-12, 2019 – Portland, OR

Group discounts are available. Private training sessions for large organizations are available upon request. Dates and times subject to change.

Space is limited, so don’t wait. Enter your name and email below and selection a training location to reserve your spot today!

Always On VPN and Windows Server 2019 NPS Bug

Note: This post updated March 19,2019 to reflect new workaround configuration guidance.

When deploying a Windows Server 2019 Network Policy Server (NPS) to support a Windows 10 Always On VPN implementation, administrators may encounter the following error when attempting to establish a VPN connection on a remote Windows 10 client.

Can’t connect to [connection name].

The connection was prevented because of a policy configured on your RAS/VPN server. Specifically, the authentication method used by the server to verify your username and password may not match the authentication method configured in your connection profile. Please contact the Administrator of the RAS server and notify them of this error.

Always On VPN and Windows Server 2019 Network Policy Server Bug
In addition, an event ID 20227 from the RasClient will be recorded in the application event log with the following error message.

The user [username] dialed a connection named [connection name] which has failed. The error code returned on failure is 812.

Always On VPN and Windows Server 2019 Network Policy Server Bug

Common Causes

Always On VPN error code 812 indicates an authentication policy mismatch between the client and the server. This often occurs when, for example, the server is configured to use Protected Extensible Authentication Protocol (PEAP), but the client is configured to use Microsoft CHAP Version 2 (MS-CHAP v2).

Troubleshooting

Carefully review the authentication policy on both the client and server to ensure they match. Next, enable firewall logging on the NPS server to log both allowed and dropped packets. Attempt another VPN connection and observe the firewall logs. In this example the firewall is dropping packets inbound on UDP port 1812.

Always On VPN and Windows Server 2019 Network Policy Server Bug

Interestingly, the default Windows firewall rule allowing inbound UDP port 1812 is enabled and set to allow for all profiles.

Always On VPN and Windows Server 2019 Network Policy Server Bug

Windows Server 2019 Bug

It appears that Microsoft’s recently released Windows Server 2019 has a bug that prevents NPS from working correctly out of the box. Specifically, it looks like the default Windows firewall rules to allow inbound UDP port 1812 (RADIUS authentication) and inbound UDP port 1813 (RADIUS accounting) do not work.

Resolution

To resolve this issue, open an elevated command window and enter the following command.

sc sidtype IAS unrestricted

Once complete, restart the server and the default Windows Firewall rules for NPS traffic will work correctly.

Additional Information

Windows 10 Always On VPN NPS Load Balancing Strategies

Comparing DirectAccess and NetMotion Mobility

Comparing DirectAccess and NetMotion Mobility With DirectAccess approaching the end of its useful lifetime, many organizations are considering alternative solutions to provide seamless, transparent, always on remote connectivity for their field-based workers. Microsoft is positioning Windows 10 Always On VPN as the replacement for DirectAccess. While it provides many new features that were missing from DirectAccess, it has its own unique limitations and shortcomings.

NetMotion Mobility Purpose-Built Enterprise VPN

NetMotion Mobility Purpose-Built Enterprise VPN Advanced Features

NetMotion Mobility

Comparing DirectAccess and NetMotion Mobility NetMotion Mobility is an excellent alternative to DirectAccess and Always On VPN, and it has many advantages over both native Microsoft offerings. NetMotion Mobility offers better security and performance. It provides deep visibility with broad client support, and the solution is easier to support than DirectAccess.

Comparing DirectAccess and NetMotion Mobility

If you’d like to learn more about how NetMotion Mobility compares with DirectAccess, you will find detailed comparison information in my Comparing NetMotion Mobility and DirectAccess article series on the NetMotion blog.

Comparing NetMotion Mobility and DirectAccess – Security
Comparing NetMotion Mobility and DirectAccess – Performance
Comparing NetMotion Mobility and DirectAccess – Visibility
Comparing NetMotion Mobility and DirectAccess – Supported Clients
Comparing NetMotion Mobility and DirectAccess – Support

NetMotion Mobility in Action

Watch the following videos to see NetMotion Mobility in action.

NetMotion Mobility Demonstration Video
NetMotion Mobility and Skype for Business Demonstration Video

DirectAccess Alternative

NetMotion Mobility is a premium remote access solution with many of the same characteristics as DirectAccess; seamless, transparent, and always on. It is feature rich with numerous compelling benefits over native Microsoft remote access technologies. Organizations seeking a solution to replace Microsoft DirectAccess would benefit greatly from NetMotion Mobility.

Learn More

If you’d like to learn more about NetMotion Mobility, or if you’d like to evaluate their solution, fill out the form below and I’ll respond with more information.

 

Always On VPN Client DNS Server Configuration

Always On VPN Client DNS Server ConfigurationDNS server configuration for Windows 10 Always On VPN clients is crucial to ensuring full access to internal resources. For Always On VPN, there are a few different ways to assign a DNS server to VPN clients.

Default DNS Servers

By default, Windows 10 clients use the same DNS server the VPN server is configured to use. This is true even if the VPN client IP address assignment method is DHCP.

Always On VPN Client DNS Server Configuration

There may be some scenarios in which this is not appropriate. For example, if the DNS server is in a DMZ network and is not configured to use internal Active Directory domain DNS servers, clients will be unable to access internal resources.

DNS Server Assignment

To configure Windows 10 Always On VPN clients to use DNS servers other than those configured on the VPN server, configure the DomainNameInformation element in the ProfileXML, as shown here.

<VPNProfile>
   <DomainNameInformation>
      <DomainName>.corp.example.net</DomainName>
      <DnsServers>10.21.12.100,10.21.12.101</DnsServers>
   </DomainNameInformation>
</VPNProfile>

Note: Be sure to include the lading “.” In the domain name to ensure that all hosts and subdomains are included.

Always On VPN Client DNS Server Configuration

Reference: https://docs.microsoft.com/en-us/windows/client-management/mdm/vpnv2-csp

DNS and NRPT

Once the DomainNameInformation element has been defined, the new DNS server assignment does NOT appear on the VPN virtual adapters interface. In fact, it will still be configured to use the DNS server assigned to the VPN server, just as before. Using the DomainNameInformation element instead configures the Name Resolution Policy Table (NRPT) and assigns the new DNS server to the namespace defined by the administrator. You can view the NRPT running the Get-DnsClientNrptPolicy PowerShell command.

Always On VPN Client DNS Server Configuration

Additional Information

Windows 10 Always On VPN and the Name Resolution Policy Table (NRPT)

Deploying Windows 10 Always On VPN with Microsoft Intune

Windows 10 Always On VPN Certificate Requirements for IKEv2

Windows 10 Always On VPN Hands-On Training

Deleting an Always On VPN Device Tunnel

Deleting an Always On VPN Device TunnelWindows 10 Always On VPN supports both a user tunnel for corporate network access, and a device tunnel typically used to provide pre-logon network connectivity and to support manage out scenarios. The process of testing Always On VPN is often an iterative one involving trial and error testing to fine tune the configuration parameters to achieve the best experience. As a part of this process it will often be necessary to delete a connection at some point. For the user tunnel the process is simple and straightforward. Simply disconnect the session and delete the connection in the UI.

Deleting an Always On VPN Device Tunnel

Deleting a device tunnel connection presents a unique challenge though. Specifically, there is no VPN connection in the UI to disconnect and remove. To delete an Always On VPN device tunnel, open an elevated PowerShell window and enter the following command.

Get-VpnConnection -AllUserConnection | Remove-VpnConnection -Force

If the device tunnel is connected when you try to remove it, you will receive the following error message.

The VPN connection [connection_name] cannot be removed from the global user connections. Cannot
delete a connection while it is connected.

Deleting an Always On VPN Device Tunnel

The device tunnel must first be disconnected to resolve this issue. Enter the following command to disconnect the device tunnel.

rasdial.exe [connection_name] /disconnect

Remove the device tunnel connection using PowerShell once complete.

Deleting an Always On VPN Device Tunnel
Additional Resources

Windows 10 Always On VPN Device Tunnel Step-by-Step Configuration using PowerShell

What’s The Difference Between DirectAccess and Always On VPN?

Windows 10 Always On VPN Recommendations for Windows Server 2016 Routing and Remote Access Service (RRAS)

Windows 10 Always On VPN Hands-On Training

DirectAccess and Always On VPN with Trusted Platform Module (TPM) Certificates

DirectAccess and Always On VPN with Trusted Platform Module (TPM) CertificatesTo enhance security when provisioning certificates for DirectAccess (computer) or Windows 10 Always On VPN (user) it is recommended that private keys be stored on a Trusted Platform Module (TPM) on the client device. A TPM is a dedicated security processor included in nearly all modern computers. It provides essential hardware protection to ensure the highest levels of integrity for digital certificates and is used to generate, store, and restrict the use of cryptographic keys. It also includes advanced security and protection features such as key isolation, non-exportability, and anti-hammering to prevent brute-force attacks.

To ensure that private keys are created and stored on a TPM, the certificate template must be configured to use the Microsoft Platform Crypto Provider. Follow the steps below to configure a certificate template required to use a TPM.

  1. Open the Certificate Templates management console (certtmpl.msc) and duplicate an existing certificate template. For example, if creating a certificate for DirectAccess, duplicate the Workstation Authentication certificate template. For Always On VPN, duplicate the User certificate template.
  2. On the Compatibility tab, ensure the Certification Authority and Certificate recipient compatibility settings are set to a minimum of Windows Server 2008 and Windows Vista/Server 2008, respectively.DirectAccess and Always On VPN with Trusted Platform Module (TPM) Certificates
  3. Select the Cryptography tab.
  4. Choose Key Storage Provider from the Provider Category drop down list.
  5. Choose the option Requests must use one of the following providers and select Microsoft Platform Crypto Provider.DirectAccess and Always On VPN with Trusted Platform Module (TPM) Certificates

Note: If Microsoft Platform Crypto Provider does not appear in the list above, got to the Request Handling tab and uncheck the option Allow private key to be exported.

Complete the remaining certificate configuration tasks (template display name, subject name, security settings, etc.) and publish the certificate template. Client machines configured to use this template will now have a certificate with private key fully protected by the TPM.

Additional Resources

Trusted Platform Module (TPM) Fundamentals

DirectAccess and Always On VPN Certificate Auto Enrollment

Always On VPN Hands-On Training Coming to Chicago

Windows 10 Always On VPN Hands-On Training Classes for 2018Recently I announced the availability of Windows 10 Always On VPN hands-on training classes. The first class is set for March 27-29 in Los Angeles. By popular demand, I’m pleased to announce that I’ll be delivering another class April 10-12 in Chicago. This training class will cover all aspects of designing, implement, and supporting an Always On VPN solution in the enterprise. These three-day courses will cover topics including…

  • Windows 10 Always On VPN overview
  • Introduction to CSP
  • Infrastructure requirements
  • Planning and design considerations
  • Installation, configuration, and client provisioning

Advanced topics will include…

  • Redundancy and high availability+
  • Cloud-based deployments
  • Third-party VPN infrastructure and client support
  • Multifactor authentication
  • Always On VPN migration strategies

Windows 10 Always On VPN Hands-On Training Classes for 2018

Register Today

Reservations are being accepted now! The cost for this 3-day hands-on training class is $4995.00 USD. Space is limited, so don’t wait to register! Fill out the form below to save your seat now.

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