OpenVPN Setup Guide with Split Tunneling on Ubuntu

Prerequisites

Ubuntu 20.04 or later
Root or sudo access
OpenVPN server configuration files

Step 1: Install OpenVPN

sudo apt update
sudo apt install openvpn -y

Step 2: Place Configuration Files

Copy your OpenVPN configuration files (e.g., .ovpn) to the /etc/openvpn/client/ directory:

sudo cp your-config.ovpn /etc/openvpn/client/

Step 3: Configure Split Tunneling

Edit the OpenVPN client configuration file to enable split tunneling. Open the file:

sudo nano /etc/openvpn/client/your-config.ovpn

Modify the following settings:

Prevent default gateway override:
```
route-nopull
```
Route only specific traffic through VPN (e.g., a corporate network 10.0.0.0/24):
```
route 10.0.0.0 255.255.255.0
```

Ensure correct DNS resolution (Optional):

dhcp-option DNS 8.8.8.8
dhcp-option DNS 8.8.4.4

Step 4: Start OpenVPN Client

Run OpenVPN using the configuration file:

sudo openvpn --config /etc/openvpn/client/your-config.ovpn --daemon

Step 5: Verify VPN Connection

Check your IP to confirm split tunneling is working:

curl ifconfig.me

To ensure only specific traffic is routed via VPN:

ip route

Step 6: Enable OpenVPN on Boot (Optional)

Create a systemd service file:

sudo nano /etc/systemd/system/openvpn-client.service

Paste the following:

[Unit]
Description=OpenVPN client
After=network.target
 
[Service]
ExecStart=/usr/sbin/openvpn --config /etc/openvpn/client/your-config.ovpn --daemon
Restart=always
 
[Install]
WantedBy=multi-user.target

Enable and start the service:

sudo systemctl enable openvpn-client
sudo systemctl start openvpn-client

Step 7: Disconnect OpenVPN

To disconnect, run:

sudo systemctl stop openvpn-client

Troubleshooting

Check OpenVPN logs for errors:
```
journalctl -u openvpn-client --no-pager
```
Restart OpenVPN service:
```
sudo systemctl restart openvpn-client
```
Verify routing rules:
```
ip route show
```

Conclusion

You have successfully configured OpenVPN with split tunneling on Ubuntu. Now, only specified traffic will pass through the VPN while the rest uses the local network.

Uptime Kuma Openvpnserversetup