Firebox Mobile VPN with L2TP Integration with AuthPoint for Microsoft Entra ID Users

Deployment Overview

This document describes how to set up AuthPoint multi-factor authentication (MFA) for Microsoft Entra ID users that use Mobile VPN with L2TP.

To configure AuthPoint MFA for Active Directory users that use Mobile VPN with L2TP, see Firebox Mobile VPN with L2TP Integration with AuthPoint.

Your WatchGuard Firebox Cloud must already be configured and deployed before you set up MFA with AuthPoint.

Contents

Integration Summary

The hardware and software used in this guide include:

  • Firebox Cloud with Fireware v12.10.4 or higher
  • AuthPoint Gateway v7.3.0 or higher
  • Windows Server 2019 with Microsoft Network Policy Server (NPS)

WatchGuard Firebox Cloud Authentication Data Flow with AuthPoint

AuthPoint communicates with various cloud-based services and service providers with the RADIUS protocol. This diagram shows the data flow of an MFA transaction for a WatchGuard Firebox Cloud.

Topology diagram

Before You Begin

Before you begin these procedures, make sure that:

  • You have a Microsoft Entra ID global administrator account.
  • You have an active Azure subscription.
  • You have installed and configured Microsoft Entra Domain Services.
  • You have installed Network Policy and Access Services, which includes Network Policy Server (NPS).
  • The NPS has joined your Microsoft Entra Domain Services managed domain.
  • You have deployed and configured the v7.3.0 or higher version of the AuthPoint Gateway on Azure (see About Gateways).
  • You have a WatchGuard Firebox Cloud deployed on Azure.
  • A token is assigned to a user in AuthPoint.

Additional charges might apply for the use of Microsoft Azure. To learn more about Microsoft Azure, go to What is Microsoft Entra Domain Services.

Configure Security Settings for Domain Services

To configure security settings for Domain Services:

  1. Log in to the Azure portal with your Microsoft Azure account credentials.
  2. Click Microsoft Entra Domain Services.
  3. Select your managed domain.
  4. From the vertical navigation pane, select Settings > Security settings.
  5. Enable the NTLM v1 Authentication option.

    6. Screenshot of Azure, enable NTLM v1 Authentication

  6. Click Save.
    The Update security settings dialog appears.
  7. Click Yes.

Configure Microsoft NPS Server

To enable users synced from Microsoft Entra ID to authenticate with MS-CHAPv2, you must configure the Microsoft Network Policy Server (NPS). The NPS is required to validate the user credentials from MS-CHAPv2 RADIUS requests against Microsoft Entra ID.

To configure Microsoft NPS Server:

  1. On the Windows server, run Server Manager.
  2. Select Tools > Network Policy Server.
    The Network Policy Server console appears.
  3. Select RADIUS Clients and Servers > RADIUS Clients.
  4. Right-click RADIUS Clients and select New.
    The New RADIUS Client window appears.
  5. In the Friendly name text box, type a name.
  6. In the Address (IP or DNS) text box, type the IP address of the AuthPoint Gateway. In our example, the IP address of the AuthPoint Gateway is 10.0.2.5.
  7. In the Shared secret and Confirm shared secret text boxes, type a shared secret key. This key is used to communicate with the RADIUS server (AuthPoint Gateway).

    You must use the same shared secret key when you configure your Firebox Cloud in the Configure RADIUS Authentication Server section and Add a RADIUS Client Resource in AuthPoint section.

    8. Screenshot of NPS, diagram1

  8. Click OK.

    9. Screenshot of NPS, diagram2

  9. Select Policies > Connection Request Policies. Make sure the default policy is enabled.

    10. Screenshot of NPS, diagram3

  10. Right-click Network Policies and select New.
    The New Network Policy window appears.
  11. In the Policy Name text box, type a name for this policy. In our example, we type ecotest.
  12. Click Next.
  13. In the Specify Conditions section, click Add.
  14. Select User Groups. Click Add > Add Groups.
  15. In the Enter the object name to select text box, type the group name. The name of this group must match the name of the Microsoft Entra ID group your users belong to.
  16. Click Check Names.
    Enter network credentials window appears, you must enter your credentials for an account with permissions for the Microsoft Entra Domain Services managed domain.
  17. To return to the New Network Policy window, click OK three times.
  18. Click Next.

    19. Screenshot of NPS, diagram4

  19. Click Next.
  20. In the Configure Authentication Methods section, clear the User can change password after it has expired check box.
  21. Click Next.

    22. Screenshot of NPS, diagram5

  22. Click Next.
  23. In the Configure Settings section, click Add. In our example, we use group authentication, if you want to use user authentication, skip Steps 23–28.
  24. From the Attributes list, select Filter-Id, then click Add.
  25. Click Add.
  26. In the Attribute Information window, in the text box, type a group name. The name of this group must match the name of the Microsoft Entra ID group your users belong to.

    27. Screenshot of nps, diagram6

  27. Click OK twice.
  28. Click Close.

    29. Screenshot of nps, diagram7

  29. Click Next.
  30. Click Finish.

    31. Screenshot of nps, diagram8

Configure Firebox Cloud

Before you configure the WatchGuard Firebox Cloud, you must deploy it on Azure. For detailed steps, see Deploy Firebox Cloud on Microsoft Azure.

To configure the Firebox Cloud, complete these steps:

  1. Configure Security Rule for Firebox Cloud
  2. Configure RADIUS Authentication Server
  3. Configure Mobile VPN with L2TP

Configure Security Rule for Firebox Cloud

To configure security rule for Firebox Cloud:

  1. Log in to the Azure portal with your Microsoft Azure account credentials.
  2. Click Resource groups.
  3. Click the Firebox Cloud resource group you created.
  4. Click the NSG-<Firebox Cloud VM name>Eth0Management network security group.
  5. From the vertical navigation pane, select Settings > Inbound security rules.
  6. Click Add to add a new security rule.
  7. From the Destination drop-down list, select IP Addresses.
  8. In the Destination IP addresses/CIDR ranges text box, type the External IP address of the Firebox Cloud, including the public and private addresses.
  9. In the Destination port ranges text box, type *.
  10. In the Priority text box, type the number between 100 and 4096. In our example, we type 1040.
  11. In the Name text box, type a name.
  12. Leave the default value for all other settings.

    13. Screenshot of Azure, Azure Firebox Cloud Security Rule

  13. Click Add.

Configure RADIUS Authentication Server

When a user authenticates with AuthPoint MFA, AuthPoint does not send a response to the Firebox until the user approves the push notification that is sent to them or until the push authentication expires.

When you configure the RADIUS authentication server, the timeout value must be greater than the combined push timeout for AuthPoint (60 seconds) and NPS (30 seconds). With the default settings on the RADIUS authentication server, if a user does not approve the push notification that is sent to them within 30 seconds (3 tries, 10 seconds each), the Firebox will fail over to another server, even though the current server is not down.

To configure the RADIUS authentication server:

  1. Log in to Fireware Web UI (https://<your Firebox IP address>:8080).
  2. From the vertical navigation pane, select Authentication > Servers.
    The Authentication Servers page opens.

    3. Screenshot of Firebox, Authentication Server

  3. From the Authentication Servers list, click RADIUS.
    The RADIUS page opens.
  4. Click Add.
    The Add page opens.
  5. In the Domain Name text box, type the domain name for this RADIUS server. Users must specify this domain name on the user login page. You cannot change the domain name after you save the settings.
  6. In the Primary Server Settings section, select the Enable RADIUS Server check box.
  7. In the IP Address text box, type the IP address of the RADIUS server (AuthPoint Gateway).
  8. In the Port text box, leave the default port setting of 1812. This is the default port used for communication with the RADIUS server (AuthPoint Gateway).

    If you already have a RADIUS server installed that uses port 1812, or if NPS and the Gateway are installed on the same server, you must use a different port for the AuthPoint Gateway.

  9. In the Shared Secret and Confirm Secret text boxes, type the shared secret key that you specified in the Configure Microsoft NPS Server section. This is the password that the RADIUS server (AuthPoint Gateway) and the RADIUS client (Firebox Cloud) will use to communicate.
  10. In the Timeout text box, type 90.
  11. Leave the default value for Group Attribute.

    12. Screenshot of Firebox, Firebox Radius Server

  12. Scroll down to the bottom of the page and click Save.

Configure Mobile VPN with L2TP

To configure Mobile VPN with L2TP:

  1. From the vertical navigation pane, select VPN > Mobile VPN.
  2. In the L2TP section, click Manually Configure.

    3. Screenshot of Firebox, Mobile VPN

  3. Select the Activate Mobile VPN with L2TP check box.
  4. Select the Authentication tab.
  5. In the Authentication Server section, from the drop-down list, select the RADIUS authentication server you created, and click Add.
  6. To make the RADIUS authentication server the default authentication server, in the Authentication Server list, select the RADIUS authentication server and click Move Up to move it to the top of the list.
    Mobile VPN with L2TP uses the default authentication server unless a user specifies an authentication server as part of the user name when they authenticate from an L2TP client.
  7. In the Users and Groups section, from the Create new drop-down list, select the RADIUS authentication server you created.
  8. From the adjacent drop-down list, select Group.

    You can add a user or a group. In our example, we add a group.

  9. Click Add.
    The Add User or Group dialog box appears.
  10. For Type, select Group.
  11. In the Name text box, type a name for the group. The name of this group must match the Microsoft Entra ID group your users belong to.

    If you add a user, the name of the user must match the name of the Microsoft Entra ID user.

  12. From the Authentication Server drop-down list, select the RADIUS authentication server you created.

    13. Screenshot of Firebox, Firebox VPN Add User or Group

  13. Click Save.
    Your new group added to the Users and Groups list.

    14. Screenshot of Firebox, L2TP Authentication

  14. Select the IPSec tab.
  15. Select the Enable IPSec check box.
  16. In the Credential Method section, select Use Pre-Shared Key.
  17. In the adjacent text box, type a pre-shared key. You must specify this same key when you configure the L2TP VPN client.

    18. Screenshot of Firebox, Firebox L2TP IPSec

  18. Click Save.

Configure AuthPoint

Before AuthPoint can receive authentication requests from the Firebox Cloud, you must:

  1. Add the Firebox as a RADIUS client resource in AuthPoint.
  2. Add a Zero Trust authentication policy for the Firebox RADIUS client resource or add the Firebox RADIUS client resource to an existing authentication policy.
  3. Bind the Firebox RADIUS client resource to the AuthPoint Gateway.

Add a RADIUS Client Resource in AuthPoint

From the AuthPoint management UI:

  1. From the navigation menu, select Resources. Click Add Resource.
    The Add Resource page opens.

  1. From the Type drop-down list, select RADIUS Client.
    Additional fields appear.

  1. On the RADIUS page, in the Name text box, type a name for this resource.
  2. In the RADIUS client trusted IP or FQDN text box, type the IP address that your RADIUS client uses to send RADIUS packets to the AuthPoint Gateway. This must be a private IP address. For Firebox, this is usually the Trusted IP address of your Firebox.
  3. Leave the default value in the Value sent for RADIUS attribute 11 (Filter-Id) drop-down list. This setting is not supported for MS-CHAPv2 authentication requests made by Microsoft Entra ID users.
  4. In the Shared Secret text box, type the shared secret key that you specified in the Configure Microsoft NPS Server and Configure RADIUS Authentication Server section. This is the password that the RADIUS server (AuthPoint Gateway) and the RADIUS client (Firebox Cloud) will use to communicate.
  5. To configure the RADIUS client resource to accept MS-CHAPv2 authentication requests, select the Enable MS-CHAPv2 check box.
    Additional fields appear.
  6. In the NPS RADIUS Server trusted IP or FQDN text box, type the IP address of your NPS RADIUS server.
  7. In the Port text box, type 1812.

    If NPS and the Gateway are installed on the same server, the port that the Gateway uses to communicate with NPS must be different than the port that the Gateway uses to communicate with the RADIUS client.

  8. In the Timeout In Seconds text box, type 30.

    9. Screenshot of authpoint, Add Radius Client Resource

  9. Click Save.

Add a Group in AuthPoint

You must have at least one user group in AuthPoint to configure MFA. If you already have a group, you do not have to add another group.

To add a WatchGuard Cloud-hosted group to the WatchGuard Cloud Directory:

  1. Go to Configure > Directories and Domain Services.
  2. Click the WatchGuard Cloud Directory domain name. If you have not yet added the WatchGuard Cloud Directory, click Add Authentication Domain and select the WatchGuard Cloud Directory.
    The New Group page appears.

Screenshot that shows the Directories and Domain Services page.

  1. In the Groups tab, click Add Group.
  2. In the Group Name text box, type a descriptive name for the group.
  3. (Optional) In the Description text box, type a description of the group.

Screen shot of the Add Group page.

  1. Click Save.
    Your group is added to the WatchGuard Cloud Directory and to AuthPoint.

Add a Zero Trust Authentication Policy

Zero Trust policies specify which resources users can authenticate to and which authentication methods they can use (Push, QR code, and OTP).

You must have at least one Zero Trust authentication policy that includes the Firebox RADIUS resource. If you already have Zero Trust authentication policies, you do not have to create a new authentication policy. You can add this resource to your existing authentication policies.

Users that do not have an authentication policy for a specific resource cannot authenticate to log in to that resource.

To configure a Zero Trust authentication policy:

  1. Go to Configure > Zero Trust. If you have a Service Provider account, you must select an account from Account Manager.
  2. Click Add Policy.
  3. Type a name for this policy.
  4. In the Target section, from the Content drop-down list, select which groups this policy applies to. You can make multiple selections to add multiple groups.
  5. In the Resources section, select the AuthPoint resources this policy applies to.
  6. In the Conditions section, select the conditions that apply to this policy. When you add a condition to an authentication policy, the policy applies only to user authentications that match the policy and the policy conditions. For example, if you add a time schedule to a policy, the policy only applies to user authentications that occur within that time schedule. Users who only have a policy that includes a time schedule do not get access to the resource when they authenticate outside of the allowed times (because they do not have a policy that applies, not because authentication is denied). For more information, go to About Zero Trust Conditions

    For RADIUS authentication, policies that have a Network Location do not apply because AuthPoint does not have the IP address of the user.

    1. (Optional) To create a new condition, click Add New Condition. After you create a new condition, you must still add the condition to the policy.
    2. From the Type drop-down list, select the type of condition to add to the policy.
    3. From the Name drop-down list, select which condition of the chosen type to add to the policy.
    4. To add more conditions, repeat Step 6.

      If you add conditions to a policy, we recommend that you create a second policy for the same groups and resources without the conditions. Assign a higher priority to the policy with the policy objects. For more information about priority, go to About Zero Trust Policy Precedence.

  7. In the Action section, select an option to specify whether to allow or deny authentications for the resources in this policy. In our example, we want to allow authentications.
    • Allow — Allow user groups in this policy access to the resources associated with this policy.
    • Deny — Deny authentications when users in the groups associated with this policy try to authenticate to the resources associated with this policy.
  8. If you allow access with this policy, select the Password and Push check boxes.

    QR code authentication is not supported for RADIUS client resources. OTP authentication is not supported for RADIUS client resources with MS-CHAPv2 enabled.

  9. Click Save.
    Your policy is created and added to the end of the policy list.
  10. Review the order of your policies and adjust as necessary. For more information about priority, go to About Zero Trust Policy Precedence.

Bind the RADIUS Resource to a Gateway

To use RADIUS authentication with AuthPoint, you must assign your RADIUS resources to the Gateway in the AuthPoint management UI and have the AuthPoint Gateway installed on Azure. The Gateway functions as a RADIUS server.

If you have not configured and installed the AuthPoint Gateway, see About Gateways.

To assign your RADIUS resources to the Gateway:

  1. From the navigation menu, select Gateway.
  2. Select the Name of the Gateway.

  3. From the RADIUS section, in the Port text box, type the port number used to communicate with the Gateway. The default ports are 1812 and 1645.

    If you already have a RADIUS server installed that uses port 1812 or 1645, you must use a different port for the AuthPoint Gateway.

  4. From the Select a RADIUS Resource drop-down list, select your RADIUS client resource.
  5. Click Save.

Sync Users to AuthPoint from Microsoft Entra ID

To sync users from Microsoft Entra ID, you must add an Azure AD external identity in the AuthPoint management UI.

In AuthPoint, Azure AD external identities represent external user databases. They connect to user databases to get user account information and validate passwords. The queries you add to an external identity specify which users to sync from your Microsoft Entra ID database. They pull user information and create AuthPoint user accounts for the users that are found.

For detailed instructions to sync users from Microsoft Entra ID, see Sync Users from Microsoft Entra ID.

Test the Integration

To test the integration of AuthPoint and the configuration of your Mobile VPN with L2TP, you authenticate with a mobile token on your mobile device. For RADIUS resources with MS-CHAPv2 enabled, you authenticate with a push notification (you receive a push notification in the AuthPoint mobile app that you must approve to authenticate).

There is a known issue where some Windows operating systems do not support Internet Protocol Security (IPsec) Network Address Translation Traversal (NAT-T) security associations to servers that are located behind a NAT device. To enable communication, you can modify a registry value on the VPN client computer. To learn how to configure the registry value, see Configure a L2TP/IPsec server behind a NAT-T device.

  1. From a Windows 10 computer, select Settings.
  2. Select Network & Internet.
  3. Select VPN.
  4. Click Add a VPN connection.
    The Add a VPN connection window opens.
  5. From the VPN provider drop-down list, select Windows (built-in).
  6. In the Connection name text box, type a name. In our example, we type VPN-L2TP.
  7. In the Server name or address text box, type the public IP address of the Firebox Cloud. In our example, the address is 203.0.113.2.
  8. From the VPN type drop-down list, select L2TP/IPsec with pre-shared key.
    Additional fields appear.
  9. In the Pre-shared key text box, type the shared secret key that you specified in the Configure RADIUS Authentication Server section.
  10. From the Type of sign-in info drop-down list, select User name and password.
  11. Click Save.
    The Add a VPN connection window closes.
  12. From the Related Settings section, click Change adapter options.
  13. Right-click the VPN you just created and select Properties.
  14. Select the Security tab.
  15. From the Data encryption drop-down list, select Require encryption (disconnect if server declines).
  16. In the Authentication section, select Allow these protocols.
  17. Select Microsoft CHAP Version 2 (MS-CHAP v2) as the only allowed protocol.
  18. Click OK to save the changes and close the Network Connections window.
  19. Select the VPN you created, then click Connect.
  20. Type your username and password.
  21. Approve the authentication request that is sent to your mobile device.
    The VPN connects successfully.

    22. A screenshot that shows the VPN connected successfully.