🌐 InterMux

Advanced Network Interface Management for Linux

Bind applications to specific network interfaces with ease

Features • Installation • Usage • Architecture • Contributing

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📋 Overview

InterMux is a powerful Linux utility that enables you to bind applications to specific network interfaces. Whether you need to route your browser through Wi-Fi while keeping your development server on Ethernet, or isolate applications for security testing, InterMux makes it simple.

Privacy Note: InterMux sets up network namespaces as root, but launches all applications as your regular user — your bookmarks, cookies, and app settings are always preserved.

🎯 Use Cases

• Multi-WAN Management: Route different applications through different internet connections
• Network Testing: Test applications on specific network interfaces
• Security Isolation: Isolate applications in separate network namespaces
• Bandwidth Management: Control which apps use which network connections
• Development: Test network-dependent applications across different interfaces

💡 Why I Made It

I was downloading a large file via torrent, and while waiting, I opened YouTube to pass the time. But the videos were stuck on low quality, buffering like crazy — even though my connection showed 300 Mbps.

Turns out, the torrent was consuming all the bandwidth, and YouTube was left starving. That’s when I had the idea: “What if I could assign different apps to different networks?”

After some research, I found that while Linux supports advanced networking, there wasn’t a simple tool to do what I needed — especially one that was GUI-friendly and straightforward.

So I built InterMux: A utility that lets me bind any app to a specific interface with ease — no messy configs, no guesswork, just full control.

✨ Features

🖥️ Core Features 🔍 Auto-detection of all network interfaces 🛣️ Custom routing tables per interface 🔒 Network namespace isolation 📊 Real-time interface monitoring 🎛️ Both CLI and GUI interfaces 👤 User-preserving — apps keep your profile & data

🌟 Interface Support 📶 Wi-Fi (wlan*, wl*) 🔌 Ethernet (eth*, en*) 📱 USB Tethering 🔵 Bluetooth Tethering 🌐 Virtual Interfaces

🚀 Installation

Prerequisites

Ubuntu / Debian / Mint

sudo apt update
sudo apt install -y python3 python3-pip iproute2 iptables policykit-1 x11-xserver-utils

Arch / EndeavourOS / Manjaro

sudo pacman -S python python-pip iproute2 iptables polkit xorg-xhost

Fedora / RHEL / Rocky

sudo dnf install -y python3 python3-pip iproute iptables polkit xorg-x11-server-utils

openSUSE

sudo zypper install python3 python3-pip iproute2 iptables polkit xorg-x11-xhost

• Note for Ubuntu 24.04+ users: Some Python modules (like brotli) may require system-level installation.

# If pip fails
sudo apt install python3-brotli

Clone and Setup

# Clone the repository
git clone https://github.com/Rishi-Bhati/intermux.git
cd intermux

# Python Virtual environment
python3 -m venv venv
source venv/bin/activate

# Install Python dependencies
pip3 install -r requirements.txt

Verify Dependencies

python3 cli.py check

🧩 Packeges Required (If everything above fails)

• You can explicitly install these packeges, if all the above given installation steps fails.

Brotli==1.1.0
click==8.2.1
markdown2==2.5.3
MarkupSafe==3.0.2
minijinja==2.11.0
page==0.3
PyYAML==6.0.2
tk==0.1.0

📖 Usage

🎨 GUI Mode (Recommended)

python3 gui/app.py

The GUI requests root via pkexec (falls back to sudo). Apps always launch as your regular user — your profile data is preserved.

GUI Features

• Interface Selection: Dropdown with all active physical interfaces (virtual adapters like veth/docker are auto-hidden)
• Application Binding: Enter app path and assign to an interface
• Running App Detection: Prompts to close & reopen (default profile) or open new instance
• Session Awareness: Auto-detects X11 or Wayland
• Dependency Banner: Warns about missing system tools

💻 CLI Mode

1. List Active Interfaces

sudo python3 cli.py list

2. Assign Application to Interface

sudo python3 cli.py assign --app /usr/lib/firefox/firefox --iface wlan0

If Firefox is already open, you'll be prompted:

[!] 'firefox' is already running (PID(s): [12345]).
    Options:
    1) Close current instance and reopen on the selected network (uses your default profile)
    2) Open a new instance with a separate profile
    3) Cancel
    Enter choice [1/2/3]:

3. Check Dependencies

python3 cli.py check

4. Clear All Paths

sudo python3 cli.py clear

5. Reset Everything

sudo python3 cli.py reset

🎥 Tutorial Video

🎥 Tutorial Video

🏗️ Architecture

intermux/
├── core/                   # Core functionality
│   ├── interface.py        # Network interface detection (cross-distro)
│   ├── router.py           # Routing table management
│   └── platform_utils.py   # ★ Distro detection, display/DNS/user helpers
├── gui/                    # GUI components
│   ├── app.py              # Main GUI application
│   └── gui.py              # Legacy GUI interface
├── cli.py                  # CLI entrypoint
├── requirements.txt        # Python dependencies
└── README.md               # This file

🔧 How It Works

1. Interface Detection: Scans system for all network interfaces using ip commands
2. Routing Tables: Creates custom routing tables in /etc/iproute2/rt_tables
3. Network Namespaces: Isolates network traffic using Linux network namespaces
4. Virtual Interfaces: Uses veth pairs to connect namespaces to physical interfaces
5. IP Forwarding: Configures NAT/masquerading for namespace connectivity
6. Privilege Separation: Namespace setup runs as root; apps launch as your user via sudo -u
7. DNS Resolution: Writes real upstream DNS servers to namespace (handles systemd-resolved stubs)

🔐 Privilege Model

Operation	Runs As
Create network namespace	root
Configure veth / routing / NAT	root
Write namespace resolv.conf	root
Launch your application	your regular user

🛠️ Advanced Configuration

Custom Routing Table IDs

Edit core/router.py:

BASE_TABLE_ID = 100  # Starting table ID
BASE_PRIORITY = 1000 # Starting priority

🐛 Troubleshooting

GUI doesn't launch on Wayland

InterMux auto-detects Wayland. If issues occur, ensure xwayland is installed:

# Arch
sudo pacman -S xorg-xwayland
# Ubuntu/Debian
sudo apt install xwayland

Permission denied errors

sudo python3 cli.py assign --app /usr/lib/firefox/firefox --iface wlan0

Interface not detected

ip link show
sudo ip link set <interface> up

No internet in namespace / DNS failures

python3 cli.py check
sudo sysctl -w net.ipv4.ip_forward=1

📝 Logs and Debugging

InterMux automatically logs all activity, commands, and errors to a persistent log file:

~/.local/share/intermux/intermux.log

This log includes detailed debug information and full stack traces, which is highly recommended to include when reporting issues.

⚠️ Known Limitations

Browser Compatibility

• ✅ Firefox: Fully supported — uses your existing profile, prompts if already running
• ❌ Chromium: Not supported due to sandboxing conflicts with network namespaces
• ✅ Most other apps: GUI and CLI applications work correctly

Platform Support

• ✅ Linux (all major distros): Arch, Ubuntu, Debian, Fedora, openSUSE, Manjaro, EndeavourOS, etc.
• ✅ X11 and Wayland: Both session types supported
• ✅ Windows 10 / 11: Phase 1 supported via SOCKS5 proxy binding — see windows/README.md

System Requirements

• Root privileges for network namespace operations
• Linux kernel with CONFIG_NET_NS
• iproute2 for network management

🤝 Contributing

Contributions are welcome! Please submit a Pull Request.

1. Fork the repository
2. Create your feature branch (git checkout -b feature/AmazingFeature)
3. Commit your changes
4. Push and open a Pull Request

📄 License

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

🙏 Acknowledgments

• Built with Python and Tkinter
• Uses Linux networking stack (iproute2)
• Inspired by the need for better network interface management

📞 Support

• 🐛 Report bugs
• 💡 Request features

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🪟 Windows Support

InterMux now supports Windows 10 and 11 via a SOCKS5 proxy engine. See windows/README.md for full installation and usage instructions.

windows/
├── gui/app.py          ← GUI (same dark theme)
├── cli.py              ← CLI (same commands)
├── core/               ← Windows-specific engine
└── intermux_windows.spec  ← PyInstaller → .exe

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Made with ❤️ for the Linux and Windows communities