Creating an OpenVPN Remote Access Client-to-Site VPN without Routing All Traffic

OpenVPN is a popular open-source VPN (Virtual Private Network) solution that allows you to securely connect to your network remotely. It provides a secure tunnel for your internet traffic, protecting your data from prying eyes. In this article, we will guide you through the process of creating an OpenVPN Remote Access Client-to-Site VPN without routing all traffic.

What is a Client-to-Site VPN?

A Client-to-Site VPN, also known as a Remote Access VPN, allows individual users to connect to a private network securely over the internet. It enables remote employees or users to access resources on the network as if they were physically present in the office.

Why not route all traffic?

By default, when you establish a VPN connection, all your internet traffic is routed through the VPN server. While this provides security, it can also slow down your internet connection and consume more bandwidth. In some cases, you may want to exclude certain traffic from going through the VPN, such as accessing local resources or streaming services.

Setting up OpenVPN Server

To create a Client-to-Site VPN without routing all traffic, you will need to set up an OpenVPN server. The server will be responsible for authenticating clients and establishing the VPN connection.

1. Install OpenVPN on your server: OpenVPN can be installed on various operating systems. Refer to the OpenVPN documentation for detailed installation instructions.
2. Generate server certificates: OpenVPN requires certificates to authenticate clients. You can generate these certificates using the Easy-RSA tool included with OpenVPN.
3. Configure the server: Open the OpenVPN server configuration file and make the following changes: local [server IP]: Replace [server IP] with the IP address of your server. push "redirect-gateway def1 bypass-dhcp": Comment out this line to prevent routing all client traffic through the VPN. push "route [network] [netmask]": Add this line for each network you want to route through the VPN. Replace [network] and [netmask] with the appropriate values.
4. Start the OpenVPN server: Start the OpenVPN server using the command specified for your operating system.

Setting up OpenVPN Client

Now that the server is configured, you need to set up the OpenVPN client on your device.

1. Install OpenVPN client: Download and install the OpenVPN client for your operating system from the official OpenVPN website.
2. Obtain client certificates: Obtain the client certificates from the server administrator. These certificates are required for authentication.
3. Configure the client: Open the OpenVPN client application and import the client certificates. Enter the server IP and port provided by the server administrator.
4. Exclude traffic from the VPN: To exclude specific traffic from going through the VPN, you need to modify the routing table on your device. Here's how to do it on Windows:
   1. Open Command Prompt as an administrator.
   2. Use the following command to view the current routing table: route print
   3. Identify the network you want to exclude and note its destination and netmask.
   4. Use the following command to remove the route for the network: route delete [network] mask [netmask]
   5. Verify that the route is removed by running route print again.
5. Connect to the VPN: Launch the OpenVPN client and click on the connect button. Enter your credentials if prompted. The client will establish a secure VPN connection.

By following the steps outlined in this article, you can create an OpenVPN Remote Access Client-to-Site VPN without routing all traffic. This allows you to access your network resources securely while excluding selected traffic from going through the VPN. Remember to consult the OpenVPN documentation or seek assistance from your network administrator if you encounter any issues.