Troubleshooting Always On VPN Error 691 and 812 – Part 3

Troubleshooting Always On VPN Error 691 and 812 – Part 2When implementing Windows 10 Always On VPN, administrators may encounter errors 691 or 812 when establishing a VPN connection. There are several different configuration issues that will result in these errors. For example they may occur when TLS 1.0 has been disabled on the RRAS server when installed on servers prior to Windows Server 2016. It can also happen if a user’s Active Directory account is configured to deny dial-in access and the NPS server is not configured to ignore user account dial-in properties. Another scenario that can result in 691/812 errors is when the Active Directory security groups are configured as conditions on the Network Policy Server (NPS) Network Policy. See below for more details.

SSTP and Error 691

When attempting to establish an Always On VPN connection using the Secure Socket Tunneling Protocol (SSTP), administrators may encounter the following error message.

“The remote connection was denied because the user name and password combination you provided is not recognized, or the selected authentication protocol is not permitted on the remote access server.”

Troubleshooting Always On VPN Error 691 and 812 – Part 2

In addition, an error 691 with event ID 20227 from the RasClient source can be found in the Application event log on the client.

“The user <domain\user> dialed a connection named which has failed. The error code returned on failure is 691.”

Troubleshooting Always On VPN Error 691 and 812 – Part 2

IKEv2 and Error 812

When attempting to establish an Always On VPN connection using Internet Key Exchange version 2 (IKEv2), administrators may encounter the following error message.

“The connection as 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.”

Troubleshooting Always On VPN Error 691 and 812 – Part 2

In addition, an error 812 with event ID 20227 from the RasClient source can be found in the Application event log on the client.

Troubleshooting Always On VPN Error 691 and 812 – Part 2

NPS Event Log

On the NPS server the administrator will find an entry in the application event log with event ID 6273 from the Microsoft Windows security auditing source and the Network Policy Server task category indicating the network policy server denied access to the user. Looking closely at this event log message shows Reason Code 48 and the following reason.

“The connection request did not match any configured network policy.”

Troubleshooting Always On VPN Error 691 and 812 – Part 2Group Membership

As stated earlier, another scenario in which administrators will encounter errors 691 and/or 812 is when the Network Policy on the NPS server is configured incorrectly. Specifically, and administrator may wish to grant access to more than one group but intend for access to be granted to users who are a member of any of them. Conversely, they may wish to require access in all specified groups to gain access to the VPN. Configuring each of these conditions is subtly different, however.

Open the NPS management console on the NPS server and follow the steps below to configure user group conditions correctly for the following scenarios.

Any Group

1. Right-click the Always On VPN network policy and choose Properties.
2. Click on the Conditions tab.
3. Click the Add button.
4. Click User Groups.
5. Click Add.
6. Click Add Groups.
7. Enter the name of the group you want to grant access to.
8. Click Ok.
9. Repeat the steps 6-8 above to specify additional groups.

Troubleshooting Always On VPN Errors 691 and 812

All Groups

1. Right-click the Always On VPN network policy and choose Properties.
2. Click on the Conditions tab.
3. Click the Add button.
4. Click User Groups.
5. Click Add.
6. Click Add Groups.
7. Enter the name of the group you want to grant access to.
8. Click Ok.
9. Repeat steps 3-8 above to specify additional groups (you must go back to the Add button on step 3!).

Troubleshooting Always On VPN Errors 691 and 812

Additional Information

Troubleshooting Always On VPN Error 691 and 812 – Part 1

Troubleshooting Always On VPN Error 691 and 812 – Part 2

Troubleshooting Always On VPN Error Code 864

When configuring an Always On VPN connection, the administrator may encounter a scenario in which a VPN connection fails using either Internet Key Exchange version 2 (IKEv2) or Secure Socket Tunneling Protocol (SSTP). On the Windows 10 client the error message states the following.

“Can’t connect to [connection name]. The remote access connection completed, but authentication failed because a certificate that validates the server certificate was not found in the Trusted Root Certification Authorities certificate store.”

Troubleshooting Always On VPN Error Code 864

In addition, the Application event log records an error message with Event ID 20227 from the RasClient source. The error message states the following.

“The user [username] dialed a connection name [connection name] which has failed. The error code returned on failure is 864.”

Troubleshooting Always On VPN Error Code 864

NPS Server Certificate

Error code 864 is commonly caused by a missing or invalid server certificate on the Network Policy Server (NPS) performing authentication for VPN clients. The NPS server must have a certificate installed in its local computer certificate store from a trusted certification authority (CA) that includes the following.

Subject Name

The subject name must match the hostname defined in the EAP configuration for VPN clients. This may be the NPS server’s hostname but could also be an alias when NPS load balancing is configured.

Troubleshooting Always On VPN Error Code 864

Enhanced Key Usage

The NPS server certificate must include the Server Authentication Enhanced Key Usage (EKU).

Troubleshooting Always On VPN Error Code 864

NPS Policy Configuration

The NPS server certificate must also be selected in the network policy used for VPN client authentication. To confirm correct certificate configuration, open the properties for the Always On VPN network policy and follow the steps below.

1. Select the Constraints tab.
2. Highlight Authentication Methods.
3. Highlight Microsoft: Protected EAP (PEAP) in the EAP Types field.
4. Click Edit.
5. Select the NPS server certificate from the Certificate issued to drop-down list.

Troubleshooting Always On VPN Error Code 864

Ensure the NPS server certificate is also used for client certificate authentication by performing the following steps.

1. Highlight Smart Card or other certificate.
2. Click Edit.
3. Select the NPS server certificate from the Certificate issued to drop-down list.
4. Click Ok.

Troubleshooting Always On VPN Error Code 864

Additional Information

Windows 10 Always On VPN Network Policy Server (NPS) Load Balancing

Always On VPN Users Prompted for Certificate

Always On VPN Users Prompted for CertificateWhen deploying Windows 10 Always On VPN using Protected Extensible Authentication Protocol (PEAP) authentication with client certificates, administrators may find the VPN connection does not establish automatically. In this specific scenario the client is prompted to select a certificate to use to authenticate to the VPN server.

Always On VPN Users Prompted for Certificate

Multiple Certificates

This can occur when certificates from multiple Certification Authorities (CAs) are issued to the user that include the Client Authentication Enhanced Key Usage (EKU). When this happens, the user is forced to select the correct certificate to use for VPN authentication.

Clearly this is less than ideal, as it not only breaks the seamless and transparent nature of Always On VPN, the user may select the wrong certificate resulting in authentication failure. Ideally the client should be configured to select the correct certificate without user interaction.

Certificate Selection

Follow the steps below to configure automatic certificate selection for VPN authentication.

  1. On a VPN client, right-click the Always On VPN connection and choose Properties.
  2. Select the Security tab.
  3. In the Authentication section click Properties below Use Extensible Authentication Protocol (EAP).
  4. In the Select Authentication Method section click Configure.
  5. In the When connecting section click Advanced.
  6. Check the box next to Certificate Issuer.
  7. Select the root CA used to issue client authentication certificates for VPN authentication.
  8. Click Ok four times to save the configuration.

Always On VPN Users Prompted for Certificate

Once complete, export the EAP configuration to XML from the VPN client and paste the new settings in Intune or in your custom ProfileXML.

Certificate Purpose

By default, a client certificate requires only the Client Authentication EKU to establish a VPN connection. In some cases, this may not be desirable. For example, consider a deployment where Client Authentication certificates are issued to all users for Wi-Fi authentication. Depending on the Network Policy Server (NPS) configuration, these certificates may also be used to authenticate to the VPN.

VPN Specific Certificate

Follow the steps below to create a user authentication certificate template to be used exclusively for VPN authentication.

Certificate Template

  1. On the CA server, open the Certificate Templates management console (certtmpl.msc).
  2. Right-click the certificate template configured for VPN authentication and choose Properties.
  3. Select the Extension tab.
  4. Highlight Application Policies and click Edit.
  5. Click Add.
  6. Click New.
  7. Enter a descriptive name for the new application policy.
  8. Copy the Object identifier for later use and click Ok four times to save the configuration.

    Always On VPN Users Prompted for Certificate

  9. If certificate autoenrollment is configured and the certificate is already provisioned to users, right-click the certificate template and choose Reenroll All Certificate holders.

Client Configuration

  1. On the VPN client, follow the steps outlined previously to configure certificate selection.
  2. In addition to choosing a certificate issuer, select Extended Key Usage (EKU).
  3. Uncheck All Purpose.
  4. Select Client Authentication and the following EKUs.
  5. Click Add.
  6. Click Add once more.
  7. Enter the name of the custom EKU policy created previously.
  8. Enter the custom EKU object identifier copied previously from the custom policy.

    Always On VPN Users Prompted for Certificate

  9. Click Ok twice.
  10. Uncheck AnyPurpose and the following EKUs.
  11. Click Ok four times to save the configuration.

Always On VPN Users Prompted for Certificate

Once complete, export the EAP configuration to XML from the VPN client and paste the new settings in Intune or in your custom ProfileXML.

Additional Information

Windows 10 Always On VPN Clients Prompted for Authentication when Accessing Internal Resources

Get-EapConfiguration PowerShell Script on GitHub

Windows 10 Always On VPN Hands-On Training

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