| title | Configure P2S VPN clients: certificate authentication: OpenVPN Client 3.x series - Windows |
|---|---|
| titleSuffix | Azure VPN Gateway |
| description | Learn how to configure VPN clients for P2S configurations that use certificate authentication. This article applies to Windows and the OpenVPN Client 3.x series. |
| author | cherylmc |
| ms.service | azure-vpn-gateway |
| ms.topic | how-to |
| ms.date | 01/29/2025 |
| ms.author | cherylmc |
| ms.custom | sfi-image-nochange |
If your point-to-site (P2S) VPN gateway is configured to use OpenVPN and certificate authentication, you can connect to your virtual network using the OpenVPN Client. This article walks you through the steps to configure the OpenVPN Connect client 3.x and connect to your virtual network. There are some configuration differences between the OpenVPN 2.x client and the OpenVPN Connect 3.x client. This article focuses on the OpenVPN Connect 3.x client.
Before beginning client configuration steps, verify that you're on the correct VPN client configuration article. The following table shows the configuration articles available for VPN Gateway point-to-site VPN clients. Steps differ, depending on the authentication type, tunnel type, and the client OS.
[!INCLUDE All client articles]
Note
The OpenVPN client is independently managed and not under Microsoft's control. This means Microsoft doesn't oversee its code, builds, roadmap, or legal aspects. Should customers encounter any bugs or issues with the OpenVPN client, they should directly contact OpenVPN Inc. support. The guidelines in this article are provided 'as is' and haven't been validated by OpenVPN Inc. They're intended to assist customers who are already familiar with the client and wish to use it to connect to the Azure VPN Gateway in a Point-to-Site VPN setup.
This article assumes that you've already performed the following prerequisites:
- You created and configured your VPN gateway for point-to-site certificate authentication and the OpenVPN tunnel type. See Configure server settings for P2S VPN Gateway connections - certificate authentication for steps.
- You generated and downloaded the VPN client configuration files. See Generate VPN client profile configuration files for steps.
- You can either generate client certificates, or acquire the appropriate client certificates necessary for authentication.
To connect to Azure using the OpenVPN Connect 3.x client using certificate authentication, each connecting client computer requires the following items:
- The OpenVPN Connect client software must be installed and configured on each client computer.
- The client computer must have a client certificate that's installed locally.
- If your certificate chain includes an intermediate certificate, see the Intermediate certificates section first to verify that your P2S VPN gateway configuration is set up to support this certificate chain. The certificate authentication behavior for 3.x clients is different than previous versions, where you could specify the intermediate certificate in the client profile.
The workflow for this article is:
- Generate and install client certificates, if you haven't already done so.
- View the VPN client profile configuration files contained in the VPN client profile configuration package that you generated.
- Configure the OpenVPN Connect client.
- Connect to Azure.
For certificate authentication, a client certificate must be installed on each client computer. The client certificate you want to use must be exported with the private key, and must contain all certificates in the certification path. Additionally, for some configurations, you'll also need to install root certificate information.
In many cases, you can install the client certificate directly on the client computer by double-clicking. However, for some OpenVPN client configurations, you might need to extract information from the client certificate in order to complete the configuration.
- For information about working with certificates, see Point-to site: Generate certificates.
- To view an installed client certificate, open Manage User Certificates. The client certificate is installed in Current User\Personal\Certificates.
Each computer needs a client certificate in order to authenticate. If the client certificate isn't already installed on the local computer, you can install it using the following steps:
- Locate the client certificate. For more information about client certificates, see Install client certificates.
- Install the client certificate. Typically, you can install a certificate by double-clicking the certificate file and providing a password (if required).
- You'll also use the client certificate later in this exercise to configure the OpenVPN Connect client profile settings.
The VPN client profile configuration package contains specific folders. The files within the folders contain the settings needed to configure the VPN client profile on the client computer. The files and the settings they contain are specific to the VPN gateway and the type of authentication and tunnel your VPN gateway is configured to use.
Locate and unzip the VPN client profile configuration package you generated. For Certificate authentication and OpenVPN, you should see the OpenVPN folder. If you don't see the folder, verify the following items:
- Verify that your VPN gateway is configured to use the OpenVPN tunnel type.
- If you're using Microsoft Entra ID authentication, you might not have an OpenVPN folder. See the Microsoft Entra ID configuration article instead.
[!INCLUDE Configuration steps]
[!INCLUDE User profile example]
If your certificate chain includes intermediate certificates, you must upload the intermediate certificates to the Azure VPN gateway. This is the preferred method to use, regardless of the VPN client you choose to connect from. In previous versions, you could specify intermediate certificates in the user profile. This is no longer supported in OpenVPN Connect client version 3.x.
When you're working with intermediate certificates, the intermediate certificate must be uploaded after the root certificate.
:::image type="content" source="./media/point-to-site-open-vpn-client-series-3/intermediate-certificate.png" alt-text="Intermediate certificate for point-to-site configuration." lightbox="./media/point-to-site-open-vpn-client-series-3/intermediate-certificate.png":::
If you experience periodic reconnects due to no traffic being sent to client, you can add the "ping-restart 0" option to the profile to prevent disconnections from causing reconnects. This is described in the OpenVPN Connect documentation as follows: --ping-restart n Similar to --ping-exit, but trigger a SIGUSR1 restart after n seconds pass without reception of a ping or other packet from remote.
See the User profile example for an example of how to add this option.
Follow up with any additional server or connection settings. See Point-to-site configuration steps.