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

Deploying Windows 10 Always On VPN with Microsoft Intune

Deploying Windows 10 Always On VPN with Microsoft IntuneWindows 10 Always On VPN is the replacement for Microsoft’s popular DirectAccess remote access solution. It provides the same seamless, transparent, always on remote connectivity as DirectAccess. Where DirectAccess relied heavily on classic on-premises infrastructure such as Active Directory and Group Policy, Always On VPN is infrastructure independent and is designed to be provisioned and managed using a Mobile Device Management (MDM) platform such as Microsoft Intune.

Intune and Always On VPN

Until recently, provisioning Windows 10 Always On VPN connections involved manually creating a ProfileXML and uploading to Intune using a custom profile. This has proven to be challenging for many, as the process is unintuitive and error prone.

A recent Intune update now allows administrators to create a basic Windows 10 Always On VPN deployment. Although it still has its limitations, it will go a long way to making the adoption of Always On VPN easier.

Prerequisites

Certificates must first be provisioned to all clients before deploying Windows 10 Always On VPN using Intune. In addition, if using a third-party VPN client, the VPN plug-in software must be installed prior to deploying the VPN profile.

Test VPN Connection

It is recommended that a test VPN connection be created on a client machine locally before deploying an Always On VPN profile using Intune. This allows the administrator to test connectivity and validate Extensible Authentication Protocol (EAP) settings. Once complete, run the following PowerShell commands to extract the EAP configuration settings to a file for later publishing with Intune.

$Vpn = Get-VpnConnection -Name [Test VPN connection name]
$Xml = $Vpn.EapConfigXmlStream.InnerXml | Out-File .\eapconfig.xml -Encoding ASCII

Deploying Always On VPN with Intune

Follow the steps below to deploy an Always On VPN connection using Intune.

Create a VPN Profile

  1. Open the Microsoft Intune management portal.
  2. Click Device configuration.
  3. Click Profiles.
  4. Click Create profile.

Deploying Windows 10 Always On VPN with Microsoft Intune

  1. Enter a name for the VPN profile.
  2. Enter a description (optional).
  3. From the Platform drop-down menu select Windows 10 and later.
  4. From the Profile type drop-down menu select VPN.
  5. In the Settings section click Configure.

Deploying Windows 10 Always On VPN with Microsoft Intune

Define VPN Profile Settings

  1. Click Base VPN.
  2. Enter a name for the connection.
  3. Enter a description and provide the Fully Qualified Domain Name (FQDN) of the VPN server. If it will be the default server select True and click Add.
  4. Enter a description and provide the FQDN for any additional VPN servers, as required.
  5. From the Connection type drop-down list choose the preferred connection type.
  6. In the Always On section click Enable.
  7. Select Enable to Remember credentials at each logon (optional).
  8. Click Select a certificate.
  9. Choose a client authentication certificate and click Ok.
  10. Paste the contents of eapconfig.xml (saved previously) in the EAP Xml field.
  11. Click Ok.

Deploying Windows 10 Always On VPN with Microsoft Intune

Define Additional Settings

You can also configure the following optional VPN settings using Intune.

  • Apps and Traffic Rules
  • Conditional Access
  • DNS Settings
  • Proxy
  • Split Tunneling

Deploying Windows 10 Always On VPN with Microsoft Intune

After configuring any required additional settings, click Create.

Assign VPN Profile

  1. Click Assignments.
  2. From the Assign to drop-down menu choose Selected Groups.
  3. Click Select groups to include.
  4. Choose an Azure Active Directory group to apply the VPN profile and click Select.
  5. Click Save.

Deploying Windows 10 Always On VPN with Microsoft Intune

Limitations

Although the ability to provision Always On VPN using Microsoft Intune without using a custom profile is welcome, it is not without its limitations. At the time of this writing, only Always On VPN user profiles can be configured. A device tunnel, which is optional, must be configured manually using a custom profile. In addition, the Intune user interface lacks the ability to define settings for the following parameters:

  • Custom IKEv2 cryptography policy
  • Exclusion routes
  • Lockdown mode

To make changes to the default settings for any of the above parameters, a ProfileXML must be created manually and provisioned with Intune using a custom policy.

Additional Information

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

Windows 10 Always On VPN Certificate Requirements for IKEv2

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

Windows 10 Always On VPN Hands-On Training

 

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

Always On VPN and the Name Resolution Policy Table (NRPT)The Name Resolution Policy Table (NRPT) is a function of the Windows client and server operating systems that allows administrators to enable policy-based name resolution request routing. Instead of sending all name resolution requests to the DNS server configured on the computer’s network adapter, the NRPT can be used to define unique DNS servers for specific namespaces.

DirectAccess administrators will be intimately familiar with the NRPT, as it is explicitly required for DirectAccess operation. Use of the NRPT for Windows 10 Always On VPN is optional, however. It is commonly used for deployments where split DNS is enabled. Here the NRPT can define DNS servers for the internal namespace, and exclusions can be configured for FQDNs that should not be routed over the VPN tunnel.

To enable the NRPT for Windows 10 Always On VPN, edit the ProfileXML to include the DomainNameInformation element.

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

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

To create an NRPT exclusion simply omit the DnsServers element. Define additional entries for each hostname to be excluded, as shown here.

<DomainNameInformation>
   <DomainName>www.example.net</DomainName>
</DomainNameInformation>
<DomainNameInformation>
   <DomainName>mail.example.net</DomainName>
</DomainNameInformation>
<DomainNameInformation>
   <DomainName>autodiscover.example.net</DomainName>
</DomainNameInformation>

Additional Information

Windows 10 VPNv2 Configuration Service Provider (CSP) Reference

Windows 10 Always On VPN Protocol Recommendations for Windows Server Routing and Remote Access Services (RRAS)

Windows 10 Always On VPN Hands-On Training

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