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10 PowerShell Commands Always On VPN Administrators Should Know

Managing a secure and reliable VPN infrastructure is critical for supporting today’s highly mobile workforce. For Always On VPN administrators, PowerShell is an indispensable tool for achieving this goal. Not only can PowerShell be used to automate the installation and configuration of Windows Server Routing and Remote Access Service (RRAS) server, but it can also be used to audit configuration and monitor system health and user activity as well. In addition, it is highly recommended that the RRAS role be installed on Server Core for optimum security and performance. Administrators must be familiar with these PowerShell commands and more to support RRAS on Windows Server Core in their environment.

RemoteAccess Module

The RemoteAccess PowerShell module should be installed when the RRAS server is configured. There are 122 commands in this module, but only a subset of those pertain to the VPN server role. Here are ten popular commands for monitoring and managing an Always On VPN RRAS server.

Configuration Review

The following PowerShell commands are useful for reviewing the current RRAS server configuration.

Get-RemoteAccess – Displays the current configuration of the VPN server. Details include installation status, TLS certificate configuration, VPN client IP address assignment method, IPv4 and IPv6 addressing information (if using the static address assignment method), authentication type, and configured RADIUS servers.

Get-VpnAuthProtocol – Displays authentication configuration details such as accepted authentication types for both user and device connections, root certification authority (CA) certificate restrictions (if enabled), and certificate advertisement and EKU restrictions if enabled.

Get-VpnServerConfiguration – Displays additional VPN server configuration information, such as the IPsec configuration for IKEv2, the number of VPN ports configured, and more.

System Health

Get-RemoteAccessHealth – Displays the current health status of various VPN server services. The command’s default output is a little noisy. I recommend filtering it as follows:

Get-RemoteAccessHealth | Where-Object HealthState -NotMatch Disabled | Format-Table -AutoSize

User Activity

The following PowerShell commands can be used to view current and historical user activity details.

Get-RemoteAccessConnectionStatistics – Displays all active VPN connections on the server.

Get-RemoteAccessConnectionStatisticsSummary – Displays cumulative information about VPN connections on the server since the last service restart or reboot, such as the total number of connections, the number of unique users, the maximum number of concurrent connections, and the amount of data transferred.

Get-RemoteAccessUserActivity – Displays all active VPN connections for a specific user or device.

Management

The following PowerShell commands are helpful for reviewing authentication and logging settings.

Get-RemoteAccessRadius – Allows the administrator to view the currently configured RADIUS servers on the VPN server.

Get-RemoteAccessAccounting – Allows the administrator to view the current accounting repository (RADIUS or inbox) on the VPN server.

Clear-RemoteAccessInboxAccountingStore – Allows the administrator to remove log data from the Inbox Accounting database. Removing log data from the database can be helpful when transitioning a test server to production or to free up disk space by reducing the size of the logging database.

Additional Modules

In addition to the PowerShell commands above, Always On VPN administrators can leverage my custom PowerShell modules for advanced server and client configuration. These modules are published in the PowerShell Gallery.

AovpnTools – PowerShell module to configure and optimize Windows RRAS servers to support Always On VPN.

Install-Module -Name AovpnTools

InboxAccountingDatabaseManagement – PowerShell module to configure and manage the Inbox Accounting database for logging system information and user activity on the VPN server.

Install-Module -Name InboxAccountingDatabaseManagement

Additional Information

Always On VPN and RRAS on Windows Server Core

Inbox Accounting Database Management

AovpnTools PowerShell Module on GitHub

Inbox Accounting Database Module on GitHub

2 Comments

by Richard M. Hicks on November 2, 2023 • Permalink

Posted by Richard M. Hicks on November 2, 2023

https://directaccess.richardhicks.com/2023/11/02/10-powershell-commands-always-on-vpn-administrators-should-know/

Always On VPN and RRAS on Windows Server Core

Windows Server Core is a refactored version of the full Windows Server operating system. Server Core does not include a Graphical User Interface (GUI) and must be managed via the command line or with PowerShell. The Routing and Remote Access Service (RRAS) is a supported workload on all supported versions of Windows Server including Windows Server 2022. Always On VPN administrators should consider installing and configuring RRAS on Windows Server Core to ensure their VPN infrastructure’s best security and performance.

Server Core Benefits

Windows Server Core is a minimal installation option of the Windows Server operating system that provides numerous benefits, particularly for environments where security, resource efficiency, and reduced maintenance overhead are essential. Here are some of the key benefits of using Windows Server Core.

Minimized Attack Surface – Windows Server Core has a smaller footprint compared to the full GUI version, which means fewer components and services are installed by default. This reduces the potential attack surface and minimizes security vulnerabilities.

Enhanced Security – With fewer components and a reduced attack surface, there are fewer potential vectors for malware or unauthorized access. This makes Windows Server Core a more secure choice for critical server roles like RRAS.

Reduced Maintenance – Since there are fewer components to update, patching and maintaining a Windows Server Core system is quicker and requires less effort. This is especially beneficial in large-scale server deployments.

Improved Stability – By removing the graphical user interface (GUI), Windows Server Core has fewer processes running in the background, leading to a more stable and predictable server environment.

Simplified Management – Windows Server Core is designed for remote administration. It allows the administrator to manage it using command-line tools, PowerShell, or remote management tools like the Remote Server Administration Tools (RSAT) and Windows Admin Center. This makes it easier to manage multiple servers from a single location.

Faster Reboots – Windows Servers require periodic reboots. With Windows Server Core, reboot times are considerably faster, resulting in less downtime during maintenance periods.

RSAT

The Remote Server Administration Tools (RSAT) can be installed on Windows clients and servers to enable remote administration using the familiar Routing and Remote Access Management console (rrasmgmt.msc) and Remote Access Management console (ramgmtui.exe) GUI tools.

Windows Client

To install the Remote Access Management tools on Windows client operating systems, navigate to Settings > Apps > Optional Features. Click Add a feature, select RSAT: Remote Access Management Tools, then click Install.

Optionally the Remote Access Management tools can be installed by running the following PowerShell command.

Add-WindowsCapability -Online -Name Rsat.RemoteAccess.Management.Tools~~~~0.0.1.0

Windows Server

To install the Remote Access Management tools on Windows Server run the following PowerShell command.

Install-WindowsFeature -Name RSAT-RemoteAccess

Windows Admin Center

The Windows Admin Center is a free remote management tool from Microsoft for managing Windows Server (core and GUI) remotely. It is especially helpful for Server Core management as it provides a GUI for many common administrative tasks.

You can download Windows Admin Center here.

Additional Information

Windows Server Core Installation Option

Windows Server Core vs. Desktop

PowerShell Remote Server Administration

Windows Admin Center

1 Comment

by Richard M. Hicks on October 2, 2023 • Permalink

Posted by Richard M. Hicks on October 2, 2023

https://directaccess.richardhicks.com/2023/10/02/always-on-vpn-and-rras-on-windows-server-core/

Always On VPN and Interface Metrics

In Windows, each network interface identified by the operating system is assigned a metric value. Interface metrics are settings that determine the priority or preference of network interfaces when there are multiple active network connections. The Windows networking stack uses these metrics to determine which network interface should be used for routing traffic when multiple network interfaces are available. Network interface metrics are critical for Always On VPN administrators to understand because they can impact how name resolution requests are processed when an Always On VPN connection is established.

Metric Values

By default, Windows automatically assigns metric values to network interfaces (including VPN interfaces) based on various factors, including the connection speed, link state, and interface type. It tries to select the most suitable interface for general internet connectivity.

Metrics and DNS

Windows will also use the network interface with the lowest metric value as the preferred interface for sending DNS queries by default. This means that DNS queries will be routed through the network interface with the lowest metric value, assuming it is available and connected. When an Always On VPN connection is established, DNS queries may fail or return unexpected results if the network interface metrics are not configured optimally.

Split DNS and Wired Ethernet

Split DNS (sometimes called ‘split brain DNS’) is when the DNS namespace is the same internally and externally. The most common scenario where interface metric settings interfere with DNS operation is when using split DNS and the endpoint is connected to the Internet with a wired Ethernet connection. In this scenario, the Ethernet interface will be assigned the same or lower interface metric value as the Always On VPN interface, which can yield unexpected results.

Viewing Metrics

Always On VPN administrators can view currently assigned interface metric values by running the following PowerShell command.

Get-NetIpInterface

Assigning Metrics

Most Always On VPN administrators will never have to change interface metric settings. However, if your implementation uses split DNS and some of your endpoints connect using wired Ethernet connections, you may need to update the interface metric settings to ensure proper DNS operation. Choose a setting for the interface metric value that is lower than the wired Ethernet interface. I’ve used a value of ‘3’ without issue for many years. Use one of the following methods to update the interface metric for Always On VPN connections.

PowerShell

Updating interface metric settings in Windows can be accomplished by running the Set-NetIpInterface PowerShell command.

Set-NetIpInterface -InterfaceAlias <connection name> -InterfaceMetric 3

Note: Using PowerShell to assign the interface metric is not persistent! While this method is suitable for local validation testing, you should use one of the following methods to implement this change permanently.

Rasphone.pbk

To assign the interface metric permanently, Always On VPN administrators can edit the following settings in the rasphone.pbk configuration file.

IpInterfaceMetric=3

Ipv6InterfaceMetric=3

Administrators can automate updating this setting using the Update-Rasphone.ps1 PowerShell script. In addition, the following scripts can be used with Microsoft Intune remediation.

Detect-DeviceIpv4InterfaceMetric.ps1

Remediate-DeviceIpv4InterfaceMetric.ps1

Detect-DeviceIpv6InterfaceMetric.ps1

Remediate-DeviceIpv6InterfaceMetric.ps1

Detect-Ipv4InterfaceMetric.ps1

Remediate-Ipv4InterfaceMetric.ps1

Detect-Ipv6InterfaceMetric.ps1

Remediate-Ipv6InterfaceMetric.ps1