Always On VPN LockDown Mode

Always On VPN LockDown ModeWhen an Always On VPN connection is provisioned to a Windows 10 client, there’s nothing to prevent a user from disconnecting or even deleting the connection. Some administrators have expressed concern about this, fearful that users may disable the VPN to improve performance or circumvent access controls when force tunneling is enabled. Also, administrators may wish to prevent users from accidentally or purposefully making changes to the configuration, or even deleting the connection entirely.

LockDown Mode

To address these concerns, Microsoft included a feature called LockDown mode for Always On VPN. Once enabled, the following conditions apply.

  • The LockDown VPN connection is always on.
  • The LockDown VPN connection cannot be disabled.
  • The user can’t make changes to or delete the LockDown connection.
  • No other VPN connections can exist on the client.
  • Force tunneling is enabled by default (split tunneling in LockDown mode is not supported).

Challenges with LockDown Mode

Always On VPN LockDown mode brings with it some unique challenges, however. Consider the following.

Limited Protocol Support

LockDown mode only supports IKEv2 and the native (built-in) VPN client. Third-party plug-in provider clients are not supported. IKEv2 is an excellent VPN protocol in terms of security, but operationally speaking it has some serious drawbacks.

Force Tunneling Only

LockDown mode uses force tunneling exclusively. All network traffic must go over the VPN connection. However, if the VPN connection is not available, the client will be unable to access any network resources at all, local or remote.

Captive Portal Issues

LockDown mode prevents clients from connecting to network resources from a network with a captive portal.

On-premises Connectivity

In LockDown mode all network traffic must flow over the VPN tunnel even if the client is on the internal network. This also means that if the VPN server is not reachable internally (unable to resolve public hostname, protocols/ports blocked by internal firewall, unable to route to VPN server, etc.) the client will not be able to access any internal or external network resources at all.

Deleting a LockDown VPN Connection

Deleting a LockDown VPN connection is also challenging. Administrators will find that trying to delete it using the UI or PowerShell often fails. To delete a LockDown Always On VPN connection, use psexec.exe to open an elevated PowerShell command window running in the system context using the following command.

.\psexec.exe -i -s C:\windows\system32\WindowsPowerShell\v1.0\powershell.exe

In the new elevated PowerShell window run the following commands to delete the LockDown VPN connection.

$ConnectionName = ‘[LockDown VPN connection name]’
$ConnectionNameEscaped = $ConnectionName -replace ‘ ‘, ‘%20’
$CimInstance = Get-CimInstance -Namespace ‘root\cimv2\mdm\dmmap’ -ClassName ‘MDM_VPNv2_01′ -Filter “ParentID=’./Vendor/MSFT/VPNv2′ and InstanceID=’$ConnectionNameEscaped'”
Remove-CimInstance -CimInstance $CimInstance

Optionally, download and run Remove-LockDownVPN.ps1 here.

Summary

While Always On VPN LockDown mode might seem like a good idea initially, its implementation is heavy-handed and practically speaking ends up causing more problems than it solves. For administrators that plan to enable this feature, carefully consider the drawbacks and limitations outlined above and their impact on supportability and the user experience.

Additional Information

Windows Always On VPN Device Tunnel Config using Microsoft Intune

Windows 10 Always On VPN Security Configuration 

Windows 10 Always On VPN Hands-On Training

 

Always On VPN Routing Configuration

Windows 10 Always On VPN Routing ConfigurationWhen configuring Windows 10 Always On VPN, the administrator must choose between force tunneling and split tunneling. When force tunneling is used, all network traffic from the VPN client is routed over the VPN tunnel. When split tunneling is used, the VPN client must be configured with the necessary IP routes to establish remote network connectivity to on-premises resources. How those routes are established is a common source of confusion. This article provides guidance for properly configuring routing for Always On VPN clients.

Class Based Routing

IP addresses are assigned to Windows 10 Always On VPN clients from either a static pool of addresses configured by the administrator or by DHCP. If split tunneling is enabled, the client will also be assigned a class-based route that is derived from the IP address assigned to it by the VPN server, by default. If the client is assigned an IP address from the Class A network, a corresponding /8 prefix is used. For Class B networks a /16 prefix is defined, and for Class C networks a /24 prefix is used.

As an example, if the VPN server assigns the client an IP address of 10.21.12.103, a route to the 10.0.0.0/8 network is added to the client’s routing table, as shown here.

Windows 10 Always On VPN Routing Configuration

Complex Networks

This default class-based route is of limited use though, and is only applicable when the internal network is simple and VPN clients are assigned IP addresses from the same subnet class. In the example above, if the entire internal network resides in the 10.0.0.0/8 Class A address space, all resources will be reachable by the VPN client. Any resources in the Class B or Class C subnet ranges would be unreachable without additional configuration.

Route Configuration

To configure routing for Windows 10 Always On VPN clients, first disable the default class-based route by defining the following element in ProfileXML as shown here.

<VPNProfile>
   <NativeProfile>
      <DisableClassBasedDefaultRoute>true</DisableClassBasedDefaultRoute>
   </NativeProfile>
</VPNProfile>

Next, enable specific routes as needed by defining the following element(s) in ProfileXML. The example below defines routes for all private RFC 1918 networks.

<VPNProfile>
   <Route>
      <Address>10.0.0.0</Address>
      <PrefixSize>8</PrefixSize>
   </Route>
   <Route>
      <Address>172.16.0.0</Address>
      <PrefixSize>12</PrefixSize>
   </Route>
   <Route>
      <Address>192.168.0.0</Address>
      <PrefixSize>16</PrefixSize>
   </Route>
</VPNProfile>

Once implemented, the VPN client’s routing table will appear as shown here.

Windows 10 Always On VPN Routing Configuration

Summary

Proper routing is crucial for ensuring full network connectivity and access to internal resources for Windows 10 Always On VPN clients. When split tunneling is employed, avoid using the default class-based route and instead define specific routes using ProfileXML as required.

Additional Information

Always On VPN Client DNS Server Configuration

Deploying Windows 10 Always On VPN with Microsoft Intune

Windows 10 Always On VPN Certificate Requirements for IKEv2

Windows 10 Always On VPN Certificate Requirements for SSTP

NetMotion Mobility for DirectAccess Administrators – Split vs. Force Tunneling

NetMotion Mobility for DirectAccess Administrators – Split vs. Force TunnelingDirectAccess employs a split tunneling network model by default. In this configuration, only network traffic destined for the internal network (as defined by the administrator) is tunneled over the DirectAccess connection. All other network traffic is routed directly over the Internet.

Force Tunneling Use Cases

For a variety of reasons, administrators may want to configure DirectAccess to use force tunneling, requiring all client traffic be routed over the DirectAccess connection, including public Internet traffic. Commonly this is done to ensure that all traffic is logged and, importantly, screened and filtered to enforce acceptable use policy and to prevent malware infection and potential loss of data.

DirectAccess and Force Tunneling

Enabling force tunneling for DirectAccess is not trivial, as it requires an on-premises proxy server to ensure proper functionality when accessing resources on the public Internet. You can find detailed guidance for configuring DirectAccess to use force tunneling here.

NetMotion Mobility and Force Tunneling

With NetMotion Mobility, force tunneling is enabled by default. So, if split tunneling is desired, it must be explicitly configured. Follow the steps below to create a split tunneling policy.

Create a Rule Set

  1. Open the NetMotion Mobility management console and click Policy > Policy Management.
  2. Click New.
  3. Enter a descriptive name for the new rule set.
  4. Click Ok.

NetMotion Mobility for DirectAccess Administrators – Split vs. Force Tunneling

Create a Rule

  1. Click New.
  2. Enter a descriptive name for the new rule.
  3. Click Ok.

NetMotion Mobility for DirectAccess Administrators – Split vs. Force Tunneling

Define an Action

  1. Click on the Actions tab.
  2. In the Addresses section check the box next to Allow network traffic for address(es)/port(s).NetMotion Mobility for DirectAccess Administrators – Split vs. Force Tunneling
  3. In the Base section select Pass through all network traffic.NetMotion Mobility for DirectAccess Administrators – Split vs. Force Tunneling

Define the Internal Network

  1. In the Policy rule definition section click the address(es)/port(s) link.NetMotion Mobility for DirectAccess Administrators – Split vs. Force Tunneling
  2. Click Add.
  3. In the Remote Address column select Network Address.
  4. Enter the network prefix and prefix length that corresponds to the internal network.
  5. Click Ok.
  6. Repeat the steps above to add any additional internal subnets, as required.
  7. Click Ok.
  8. Click Save.
  9. Click Save.NetMotion Mobility for DirectAccess Administrators – Split vs. Force Tunneling

Assign the Policy

  1. Click on the Subscribers tab.
  2. Choose a group to assign the policy to. This can be users, groups, devices, etc.NetMotion Mobility for DirectAccess Administrators – Split vs. Force Tunneling
  3. Click Subscribe.
  4. Select the Split Tunneling policy.
  5. Click Ok.NetMotion Mobility for DirectAccess Administrators – Split vs. Force Tunneling

Validation Testing

With split tunneling enabled the NetMotion Mobility client will be able to securely access internal network resources over the Mobility connection, but all other traffic will be routed over the public Internet. To confirm this, first very that internal resources are reachable. Next, open your favor Internet search engine and enter “IP”. The IP address you see should be the IP address of the client, not the on-premises gateway.

Summary

I’ve never been a big fan of force tunneling with DirectAccess. Not only is it difficult to implement (and requires additional infrastructure!) the user experience is generally poor. There are usability issues especially with captive portals for Wi-Fi, and performance often suffers. In addition, enabling force tunneling precludes the use of strong user authentication with one-time passwords.

With NetMotion Mobility, force tunneling is on by default, so no configuration changes are required. The user experience is improved as NetMotion Mobility intelligently recognizes captive portals. Performance is much better too. In addition, NetMotion Mobility is more flexible, allowing for the use of OTP authentication with force tunneling. Also, with NetMotion Mobility force tunneling is not a global setting. You can selectively apply force tunneling to users and/or groups as necessary.

Additional Information

NetMotion Mobility as an Alternative for Microsoft DirectAccess

NetMotion Mobility for DirectAccess Administrators – Trusted Network Detection

Enabling Secure Remote Administration for the NetMotion Mobility Console

NetMotion Mobility Device Tunnel Configuration