OpenVPN Unable to Assign IP Address Using Synology DSM

OpenVPN is a popular virtual private network (VPN) software that allows users to securely connect to a private network over the internet. Synology DSM (DiskStation Manager) is a web-based operating system used in Synology network-attached storage (NAS) devices. However, sometimes users may encounter an issue where OpenVPN is unable to assign an IP address using Synology DSM. In this article, we will explore the possible causes of this issue and provide troubleshooting steps to resolve it.

1. Check Network Settings

The first step in troubleshooting this issue is to ensure that the network settings on your Synology NAS are correctly configured. Follow these steps:

1. Log in to your Synology DSM web interface.
2. Go to "Control Panel" and click on "Network".
3. Check the "General" tab and verify that the network settings, including IP address, subnet mask, gateway, and DNS servers, are correct.
4. If any changes are required, click on "Edit" to modify the settings accordingly.
5. Click "Apply" to save the changes.

2. Check OpenVPN Server Settings

If the network settings are correct, the next step is to check the OpenVPN server settings. Follow these steps:

1. Go to "Control Panel" and click on "VPN Server".
2. Click on the "OpenVPN" tab.
3. Ensure that the "Enable OpenVPN server" option is checked.
4. Verify that the "Network settings" are configured correctly. This includes the "IP address range" and "Subnet mask".
5. If any changes are required, modify the settings accordingly and click "Apply".

3. Check Firewall Settings

Firewall settings on your Synology NAS may also cause issues with OpenVPN IP address assignment. Follow these steps to check and configure the firewall settings:

1. Go to "Control Panel" and click on "Security".
2. Click on the "Firewall" tab.
3. Ensure that the "Enable firewall" option is checked.
4. Click on "Edit Rules" to configure the firewall rules.
5. Add a new rule to allow OpenVPN traffic. Set the source IP as "OpenVPN" and the destination IP as "Synology NAS".
6. Save the rule and click "Apply" to save the firewall settings.

4. Restart OpenVPN Service

If the above steps did not resolve the issue, try restarting the OpenVPN service on your Synology NAS. Follow these steps:

1. Go to "Control Panel" and click on "VPN Server".
2. Click on the "OpenVPN" tab.
3. Toggle the "Enable OpenVPN server" option to disable it.
4. Wait for a few seconds and toggle the option back to enable it.
5. Click "Apply" to save the changes.

5. Update OpenVPN and Synology DSM

If the issue persists, it is recommended to update both OpenVPN and Synology DSM to the latest versions. Follow these steps:

1. Go to "Package Center" in your Synology DSM web interface.
2. Click on "Installed" and search for "OpenVPN".
3. If an update is available, click on "Update".
4. Similarly, search for "Synology DSM" and update it if a newer version is available.
5. Restart your Synology NAS after the updates are installed.

If you have followed all the troubleshooting steps above and are still unable to assign an IP address using OpenVPN and Synology DSM, it is recommended to seek further assistance from the Synology support team or consult the user forums for additional guidance.