How to Install OpenVPN on RHEL/CentOS and Other Linux Flavors? Print

Introduction

OpenVPN is a robust and highly configurable VPN solution used for secure communication over the internet. This guide covers the steps to install and configure OpenVPN on RHEL, CentOS, and other Linux distributions.

Prerequisites

• A system running RHEL, CentOS, Ubuntu, or other Linux flavors.
• Root or sudo privileges.
• Basic knowledge of networking and VPN concepts.

Installing OpenVPN

On RHEL/CentOS

Follow these steps to install OpenVPN:

sudo yum install epel-release -y
sudo yum install openvpn easy-rsa -y

On Ubuntu/Debian

sudo apt update
sudo apt install openvpn easy-rsa -y

On Fedora

sudo dnf install openvpn easy-rsa -y

Configuring OpenVPN

After installation, follow these steps to configure OpenVPN:

Step 1: Set Up the Easy-RSA Environment

make-cadir ~/openvpn-ca
cd ~/openvpn-ca
source ./vars

Initialize the Public Key Infrastructure (PKI):

./clean-all
./build-ca

Step 2: Generate Server Certificates and Keys

./build-key-server server

Generate Diffie-Hellman parameters:

./build-dh

Step 3: Configure the OpenVPN Server

Copy the sample server configuration file:

sudo cp /usr/share/doc/openvpn*/sample/sample-config-files/server.conf /etc/openvpn/

Edit the configuration file to suit your environment:

sudo nano /etc/openvpn/server.conf

Step 4: Enable and Start OpenVPN

sudo systemctl enable openvpn@server
sudo systemctl start openvpn@server

Setting Up OpenVPN Clients

Follow these steps to configure clients:

Step 1: Generate Client Certificates

cd ~/openvpn-ca
source ./vars
./build-key client1

Step 2: Create Client Configuration File

Copy the sample client configuration file:

cp /usr/share/doc/openvpn*/sample/sample-config-files/client.conf ~/client1.ovpn

Edit the configuration file:

nano ~/client1.ovpn

Step 3: Transfer Configuration to Client

Transfer the client1.ovpn file and certificates to the client machine securely using SCP or another method.

Troubleshooting

• OpenVPN Service Fails to Start: Check the logs:

  sudo journalctl -u openvpn@server

• Client Connection Issues: Ensure the client configuration matches the server settings.
• Network Connectivity Problems: Verify firewall and routing settings.

Tips and Special Advice

• Use strong encryption methods for added security.
• Regularly update OpenVPN to the latest version.
• Test configurations in a staging environment before deploying to production.

Conclusion

Installing and configuring OpenVPN on Linux is a straightforward process that provides secure communication over the internet. This guide covers the essential steps for setting up OpenVPN on various Linux distributions.