Guard VPN

A lightweight VPN built with Go that provides secure communication between clients and servers using encrypted tunnels, virtual network interfaces, and UDP-based packet forwarding.

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Overview

Guard VPN is a lightweight Virtual Private Network (VPN) solution developed in Go that enables secure communication between distributed systems over the internet.

It creates encrypted tunnels between clients and servers using UDP sockets and virtual network interfaces (TUN devices), allowing private network communication as if the devices were connected to the same local network.

Guard VPN is designed for learning and experimentation with networking concepts such as:

• VPN architecture
• TUN interfaces
• UDP communication
• Packet forwarding
• Routing
• Secure remote connectivity

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Features

Feature	Description
🌐 Virtual Network Interface	Uses Linux TUN devices to create virtual private networks
⚡ UDP-Based Communication	Fast packet transmission using UDP sockets
🔄 Packet Forwarding	Transfers IP packets between clients and the VPN server
🖥️ Cross-Network Connectivity	Connect devices across different networks securely
📚 Educational Project	Helps understand VPN internals and Linux networking

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Architecture

+-------------+       UDP Tunnel       +-------------+
| VPN Client  | <--------------------> | VPN Server  |
|   tun0      |                        |   tun0      |
+-------------+                        +-------------+
       |                                      |
       +---------- Virtual Private Network ---+

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Tech Stack

Layer	Technology
Language	Go (Golang)
Operating System	Linux
Networking	UDP Sockets
Virtual Interfaces	TUN/TAP
System Programming	Linux Networking APIs

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Getting Started

Prerequisites

• Go 1.22+
• Linux Operating System
• Git

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Installation

1. Clone Repository

git clone https://github.com/johngithiyon/Guard.git

cd Guard

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2. Install Dependencies

go mod tidy

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3. Build the Server

go build -o guard-server ./cmd/server

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4. Build the Client

go build -o guard-client ./cmd/client

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Running the VPN

Start the Server

sudo ./guard-server

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Start the Client

sudo ./guard-client

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Learning Objectives

This project demonstrates:

• VPN implementation from scratch
• Linux networking internals
• TUN/TAP interfaces
• UDP socket programming
• Routing and packet forwarding
• Secure communication over public networks

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Future Improvements

• Encryption using AES or ChaCha20
• Authentication mechanism
• Cross-platform support

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License

This project is licensed under the MIT License — see the LICENSE file for details.

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Built with ❤️ using Go and Linux Networking