Network Redundancy Script

Table of Contents

• Introduction
• Prerequisites
• How to Run
• Run as a Service (systemd)
• Run as a Service (rc.local)
• Removing the Service
• Flowchart

Introduction

This script is designed to create a virtual bridge that combines a specified main connection with other active network interfaces. It continuously monitors the network interfaces, dynamically adjusting the virtual bridge for network redundancy. This is particularly useful in scenarios where multiple network connections are available, providing a seamless and automatic failover mechanism.

Prerequisites

Ensure your system meets the following requirements:

• Linux operating system.
• The ip, brctl, and awk commands are available.
• sudo privileges are required to execute the script.

How to Run

1. Clone or Download the Script:

   git clone https://github.com/1999AZZAR/network-redundancy.git

   Replace the URL with the actual path if you are downloading manually.

2. Make the Script Executable:

   chmod +x /path/to/network_redundancy.sh

3. Run the Script with sudo:

   sudo /path/to/network_redundancy.sh

   This will execute the script with elevated privileges necessary for managing network interfaces.

Run as a Service (systemd)

1. Create a systemd Service File: Create a new service file for systemd. Open an editor and create /etc/systemd/system/network_redundancy.service with the following content:

   [Unit]
   Description=Network Redundancy Script
   
   [Service]
   ExecStart=/path/to/network_redundancy.sh
   Restart=always
   User=root
   Group=root
   
   [Install]
   WantedBy=multi-user.target

   Replace /path/to/network_redundancy.sh with the actual path to your script.

2. Reload systemd:

   sudo systemctl daemon-reload

3. Enable the Service to Start on Boot:

   sudo systemctl enable network_redundancy.service

4. Start the Service:

   sudo systemctl start network_redundancy.service

   The script will now run as a service and automatically start on system boot.

Run as a Service (rc.local)

1. Edit the rc.local File: Edit the rc.local file using your preferred text editor:

   sudo nano /etc/rc.local

2. Add the Command to Run the Script: Add the following line before exit 0:

   /path/to/network_redundancy.sh &

   Replace /path/to/network_redundancy.sh with the actual path to your script.

3. Make rc.local Executable:

   sudo chmod +x /etc/rc.local

4. Reboot Your System:

   sudo reboot

   The script will run automatically on system boot using rc.local.

Removing the Service

1. If Using systemd:

   sudo systemctl disable network_redundancy.service
   sudo systemctl stop network_redundancy.service

2. If Using rc.local: Remove the line added to rc.local.

3. Delete the systemd Service File (if created):

   sudo rm /etc/systemd/system/network_redundancy.service

4. Reboot Your System:

   sudo reboot

5. Remove the Script (if no longer needed):

   rm /path/to/network_redundancy.sh

   The script and associated configurations will be removed from your system.

Flowchart

graph TB

subgraph Initialization
  A[Define Variables]
  B[Define Functions]
  C[Trap Exit Signal]
end

subgraph Cleanup
  D[Cleanup]
end

subgraph Main Loop
  E[Get Active Interfaces]
  F[Check Changes in Interfaces]
  G[Update Virtual Bridge]
  H[Set Virtual Bridge as Main Connection]
end

A --> B --> C --> D --> E --> F --> G --> H --> E