DNS Auto Switcher Documentation

📝 Description

A Python script that automatically tests and switches to the fastest available DNS server at regular intervals. Designed for Linux systems using NetworkManager.

🛠 Requirements

• Python 3.x
• Linux with NetworkManager (nmcli)
• dig command (from dnsutils package)
• Root privileges

🚀 Installation

# Install dependencies
sudo apt-get install dnsutils network-manager  # Debian/Ubuntu
sudo yum install bind-utils NetworkManager    # RHEL/CentOS

# Make script executable
chmod +x dns_switcher.py

⚙️ Configuration

DNS Server List

DNS_SERVERS = {
    "Google": ["8.8.8.8", "8.8.4.4"],
    "Cloudflare": ["1.1.1.1", "1.0.0.1"],
    # ... (17 other providers)
}

Check Interval

CHECK_INTERVAL = 300  # 5 minutes (adjust as needed)

🏃‍♂️ Usage

sudo ./dns_switcher.py

Press Ctrl+C to stop the script

🔧 Functions

test_dns_speed(servers)

• Tests response times using dig command
• Returns: {"Provider": latency_ms, ...}

set_dns(servers)

• Configures DNS via NetworkManager
• Returns: True if success, False if failed

main()

• Main control loop
• Handles testing, switching, and interval timing

🖥️ Output Example

==================================================
🕒 Testing for fastest DNS (Interval: 300s)...

📊 Test Results:
Google: 24.53 ms
Cloudflare: 18.21 ms
Quad9: 32.67 ms

⚡ Fastest DNS changed to: Cloudflare (18.21 ms)
✅ DNS changed to Cloudflare: 1.1.1.1, 1.0.0.1

🐛 Troubleshooting

Issue	Solution
DNS changes fail	Run with sudo
No test results	Install dnsutils
Connection errors	Check NetworkManager

📜 License

MIT License - Free for modification and distribution

💡 Notes

• Changes persist until network restart
• Tested on Ubuntu/Fedora
• Add providers by editing DNS_SERVERS dictionary