Always On VPN NPS Auditing and Logging

The Network Policy Server (NPS) event log is incredibly valuable for administrators when troubleshooting Always On VPN user tunnel connectivity issues. Administrators can find these pertinent events by opening the Event Viewer on the NPS server (eventvwr.msc) and navigating to Custom View > Server Roles > Network Policy and Access Services.

Event Logs

When configured correctly, event logs will record the disposition of all authentication requests, allowed or denied. The two most common recorded events are event IDs 6272 (access granted) and 6273 (access denied).

NPS Event ID 6272 – Access granted.

NPS Event ID 6273 – Access denied.

Auditing

In some cases, administrators may find none of these events recorded even though user authentication is working correctly. Here, the only events recorded are NPS informational events indicating which domain controller the NPS server is using to perform authentication.

The lack of 6272 and 6273 events in the event log indicates that auditing for NPS events is not enabled. Open an elevated PowerShell window and run the following command to view the current auditing setting for NPS events.

auditpol.exe /get /subcategory:”Network Policy Server”

Open an elevated PowerShell window and run the following command to enable auditing for NPS events.

auditpol.exe /set /subcategory:”Network Policy Server” /success:enable /failure:enable

Group Policy

Alternatively, consider using Active Directory group policy to enforce the NPS server auditing settings. Open the Group Policy Management Console (GPMC) and create a new GPO. Next, navigate to Computer Configuration > Policies > Windows Settings > Security Settings > Local Policies > Audit Policy > Audit account logon events and select the option to audit both success and failure attempts.

Once complete, link this GPO to the OU where the NPS servers reside.

Missing Events

If auditing is enabled and there are no recorded 6272 or 6273 events, the NPS server did not receive any authentication requests from the VPN server. Review the event logs on any other NPS servers if there is more than one configured. In addition, this may indicate that network communication between the VPN and NPS server is blocked. Ensure network connectivity and name resolution are working as expected.

Troubleshooting Guides

Are you interested in learning more about Always On VPN troubleshooting? My Always On VPN book contains an entire chapter dedicated to troubleshooting. Also, my Always On VPN video training course on Pluralsight includes a module on troubleshooting. The video training course is available to Pluralsight subscribers only. If you don’t have a Pluralsight subscription, you can sign up for a free trial here.

Additional Information

Troubleshooting Always On VPN Errors 691 and 812

Troubleshooting Always On VPN Errors 691 and 812 – Part 2

Troubleshooting Always On VPN Errors 691 and 812 – Part 3

Always On VPN NPS Load Balancing

Inbox Accounting Database Management

The Routing and Remote Access Service (RRAS) role in Windows Server is a popular VPN server choice for administrators deploying Windows Always On VPN. It is easy to configure, scales well, and is cost-effective. After installing RRAS, administrators can optionally enable inbox accounting to log historical data and generate user access and activity reports as described in Always On VPN RRAS Monitoring and Reporting.

Inbox Accounting Database

A Windows Internal Database (WID) is automatically installed and configured for data storage when inbox accounting is enabled.

WID is nothing more than a basic instance of Microsoft SQL Server. As such, the database will require periodic maintenance to perform optimally.

Inbox Accounting Database Management Scripts

I have created a series of PowerShell scripts to address the inbox accounting database management requirements for organizations using Windows Server RRAS. Scripts are available to perform the following inbox accounting database management tasks.

  • Optimize the inbox accounting database.
  • View the size of the inbox accounting database files.
  • Compress the size of the inbox accounting database.
  • Back up the inbox accounting database to a file on disk.
  • Restore the inbox accounting database from a backup file.
  • Move the inbox accounting database file to a different location.
  • Remove the inbox accounting database.

Optimize Database

A known issue with the inbox accounting database can result in high CPU and memory utilization for very busy RRAS VPN servers. Specifically, a crucial index is missing from one of the tables in the logging database. This issue persists in Windows Server 2022. To correct this issue, download and run the following PowerShell script on each RRAS VPN server in the organization.

Optimize-InboxAccountingDatabase.ps1

View Database Size

The database can grow rapidly depending on how busy the RRAS server is. Administrators can view the current database file sizes by downloading and running the following PowerShell script on the RRAS server.

Get-InboxAccountingDatabaseSize.ps1

Compress Database

Over time, the database can become fragmented, decreasing performance. Compressing the database can improve performance and result in significant recovery of disk space. To compress the inbox accounting database, download and run the following PowerShell script on each RRAS server in the organization.

Compress-InboxAccountingDatabase.ps1

In this example, compressing the database reduced its size by more than 8MB, resulting in a nearly 70% reduction in disk space usage.

Backup Database

Administrators may wish to back up the inbox accounting database before purging older records from the inbox accounting database. Also, backing up the database preservers access records when migrating to a new server. To back up the inbox accounting database, download and run the following PowerShell script on each RRAS server in the organization.

Backup-InboxAccountingDatabase.ps1

Restore Database

Naturally, to restore the inbox accounting database from a previous backup, administrators can download and run the following PowerShell script.

Restore-InboxAccountingDatabase.ps1

Restoring a database from backup will erase all records in the current database. It does not append. Proceed with caution!

Move Database Files

Inbox accounting database and log files are located in C:\Windows\DirectAccess\Db by default.

However, storing database and log files on the system drive is not ideal. A better alternative is to place the inbox accounting database and log files on a separate disk for optimum performance. To move the inbox accounting database, download and run the following PowerShell script on each VPN server in the organization.

Move-InboxAccountingDatabase.ps1

Moving inbox accounting files may not be formally supported by Microsoft. Use caution when making this change.

Remove Database

Occasionally an inbox accounting database becomes corrupt and can no longer be managed. If this happens, completely removing the database is required. It is essential to know that simply disabling and re-enabling inbox accounting on the VPN server does not delete the database. To delete the database completely, download and run the following PowerShell script.

Remove-InboxAccountingDatabase.ps1

PowerShell Module

To simplify things, the PowerShell scripts described in this article are available in a PowerShell module that can be installed from the PowerShell gallery using the following command.

Install-Module InboxAccountingDatabaseManagement

Additional Information

Windows Always On VPN RRAS Inbox Accounting Database Management PowerShell Module

Windows Always On VPN RRAS Monitoring and Reporting

Windows Always On VPN PowerShell Scripts on GitHub

Always On VPN Book Available for Pre-Order

Great news! My new book, Implementing Always On VPN, is now available for pre-order on Amazon.com. This new book, scheduled for release in late 2021, is a comprehensive implementation guide for Windows 10 Always On VPN. Drawing on many years of experience deploying Always On VPN for organizations worldwide, it covers all aspects of an Always On VPN deployment, including planning and design, prerequisite gathering, infrastructure preparation, and client deployment.

In addition, it contains detailed, prescriptive guidance for advanced configuration options such as application and traffic filtering and proxy server configuration. Cloud deployments using Azure VPN gateway and Virtual WAN are covered, and it includes guidance for configuring Azure MFA and Conditional Access.

Also, the book includes thorough guidance for provisioning certificates using Microsoft Endpoint Manager/Intune using both PKCS and SCEP. It outlines options for high availability for VPN and authentication infrastructure and provides details for ongoing system maintenance and operational support.

Finally, the book has an entire chapter dedicated to troubleshooting and resolving common (and not so common!) issues encountered with Windows 10 Always On VPN.

Reserve your copy today. Pre-order Implementing Always On VPN now!

Chapter List

  1. Always On VPN Overview
  2. Plan an Always On VPN Deployment
  3. Prepare the Infrastructure
  4. Configure Windows Server for Always On VPN
  5. Provision Always On VPN clients
  6. Advanced Configuration
  7. Cloud Deployments
  8. Deploy Certificates with Intune
  9. Integrating Azure MFA
  10. High Availability
  11. Monitor and Report
  12. Troubleshooting
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