Part 2- Setting up OpenVPN Clients

Jun 09, 2017 Written by Saravanan Platform Operations Engineer

Introduction

OpenVPN is based on a client/server architecture. It must be installed on both VPN extremities, one is designated as server the other one as client.

This tutorial will help to install and configure a OpenVPN client.

Prerequisites

To follow this tutorial :

You will need Ubuntu 16.04 in your server that is designated as OpenVPN client in the below discussion.
You have successfully finished Part 1: Setting up OpenVPN Server and have the credentials to be shared with the client machine.
In our case we will use the credentials stored here.

Step 1: Install the OpenVPN

On Ubuntu or Debian, you can install it by typing.

$ sudo apt-get update
$ sudo apt-get install openvpn

Check to see if your distribution includes a /etc/openvpn/update-resolv-conf script.
```
$ ls /etc/openvpn           
update-resolve-conf
```

Step 2: Send configuration files from your local into OpenVPN client

If you have the copy of client.tar.xz received via email, then untar it in your local machine.

Let us send those files into your OpenVPN client. These instruction are valid for a linux environment.

  local $ sftp user@openvpn_client_ip:client-configs/files/client1.ovpn ~/
  local $ sftp user@openvpn_client_ip:openvpn-ca/keys/ca.crt ~/
  local $ sftp user@openvpn_client_ip:openvpn-ca/keys/client.key ~/
  local $ sftp user@openvpn_client_ip:openvpn-ca/keys/client.crt ~/

Step 3: SSH from your local into OpenVPN client

Now, let us establish a private tunnel between OpenVPN client and your server.

Run the command in OpenVPN client:

  client$ sudo openvpn --config /etc/openvpn/client1.ovpn

This should connect you to your OpenVPN server. Please don’t exit out of this window.

Step 4: Test Your VPN Connection

Now connect your local laptop as OpenVPN client by doing Step 2, 3. We now have the following.

Check your local laptop connected which is connected into OpenVPM server. Open a terminal and type ifconfig tun0 . It will show the OpenVPN bridge details.

4: tun0: <POINTOPOINT,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN group default qlen 100
link/none
inet 10.8.0.1 peer 10.8.0.2/32 scope global tun0
valid_lft forever preferred_lft forever

Now our local laptop and OpenVPN server are connected via private ipaddress. You can SSH using the private ip and your credentials of the OpenVPN server.

Conclusion

These are the steps to configure the OpenVPN as a client. Now you access the Internet safely and securely from your computer or laptop when connected to an untrusted network.