OpenVPN Setup (Server & Client)

Environment

• VPN Server

  Field	Spec or Version
  CPU	QEMU Virtual CPU version 2.5+ (2 Cores)
  RAM	2G
  OS	Ubuntu 24.04.1 LTS (Noble Numbat)
  Network	interface ens18 with static IP 192.168.3.100/24
  DNS	192.168.3.1 (Private DNS Server)

• VPN Client

  Field	Spec or Version
  CPU	QEMU Virtual CPU version 2.5+ (2 Cores)
  RAM	2G
  OS	Ubuntu 24.04.1 LTS (Noble Numbat)
  Network	interface ens18 with static IP 192.168.5.100/24
  DNS	192.168.5.1 (Private DNS Server)

Server - Package Installation

apt install -y openvpn

Server - Configuration

• Copy from sample configuration file

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

• Edit the copied file

  port 1194
  proto tcp
  
  # Use routing mode instead of bridge mode
  dev tun
  
  ca ca.crt
  cert example.fake.crt
  key example.fake.key
  dh dh.pem
  
  topology subnet
  server 192.168.7.0 255.255.255.0
  
  # Add route for subnet on server to connected VPN clients
  push "route 192.168.3.0 255.255.255.0"