All configuration is performed in Virtual Private Server (VPS). If you have the intention to use VPS, make sure your provider support and enable TUN/TAP module in your VPS container. For the following example, I’m using Ramnode VPS (affiliate link) because of their good support, you can enable and disable TUN/TAP easily on your own and their price is relatively cheap. For myself, I’m subscribed to their OpenVZ SSD VPS (128MB RAM, 10GB SSD Space) for 20.40 USD Annually (USD1.70 per month). Don’t forget to enter the promotional code RN15OFF to enjoy 15% Recurring Discount off your VPS price.

Enable TUN/TAP

Go to your VPS Control Panel, and at the bottom you will see an option to enable TUN/TAP module. Turn it on and reboot your VPS.

Once boot up, check whether the module is enabled or not by executing below command:

[email protected]:~# cat /dev/net/tun

If you receive the message File descriptor in bad state your TUN/TAP device is ready for use.
If you receive the message No such device the TUN/TAP device was not successfully created.

Download and Install OpenVPN Access Server

Go to OpenVPN Access Server download page and select your architecture. I’m using Debian 7 32bit OS.

[email protected]:/home# wget http://swupdate.openvpn.org/as/openvpn-as-2.0.3-Debian7.i386.deb

Perform installation by executing:

[email protected]:/home# dpkg -i openvpn-as-2.0.3-Debian7.i386.deb

Change openvpn default password:

[email protected]:/home#  passwd openvpn

Now you can access OpenVPN Admin UI from below link:
Admin UI: https://serverip:943/admin
Client UI: https://serverip:943/