NatTypeTester-NG

A cross-platform NAT type detection tool built with Python and PySide6 (Qt).

Download

Pre-built binaries are available from the latest release. No Python installation required.

Platform	File	Notes
Linux	NatTypeTester-NG-linux	Single executable, mark as executable with chmod +x
macOS	NatTypeTester-NG-macos	Single executable, mark as executable with chmod +x
Windows	NatTypeTester-NG-windows.exe	Double-click to run

Quick Start

Linux / macOS:

chmod +x NatTypeTester-NG-linux   # or NatTypeTester-NG-macos
./NatTypeTester-NG-linux

Windows: Double-click NatTypeTester-NG-windows.exe or run from a terminal.

Overview

NatTypeTester-NG uses STUN (Session Traversal Utilities for NAT) protocols to identify what type of NAT a computer is behind. This is a port of the original .NET/WPF application to Python/Qt for true cross-platform support.

Features

• Dual Protocol Support

  • Classic RFC 3489 NAT type detection
  • Modern RFC 5389/5780 behavior classification

• Multiple Transports

  • UDP
  • TCP (modern test, currently not supported)
  • TLS-over-TCP (modern test, currently not supported)

• Pre-configured STUN Servers

  • Google, Xiaomi, Hot Chilli, Syncthing, and more
  • Custom server support

• Modern UI

  • Dark/light theme toggle
  • Clear results display
  • Copy results to clipboard

NAT Types Detected

Classic (RFC 3489)

• Open Internet
• Symmetric UDP Firewall
• Full Cone NAT
• Restricted Cone NAT
• Port Restricted Cone NAT
• Symmetric NAT
• UDP Blocked

Modern (RFC 5389/5780)

Mapping Behavior:

• Direct (no NAT)
• Endpoint Independent
• Address Dependent
• Address and Port Dependent

Filtering Behavior:

• Endpoint Independent
• Address Dependent
• Address and Port Dependent

Building from Source

Prerequisites

• Python 3.11 or higher
• pip package manager

Setup Development Environment

1. Clone the repository:

git clone https://git.jdneer.com/jd/NatTypeTester-NG.git
cd NatTypeTester-NG

2. Run the setup script:

./init.sh

Or manually:

python -m venv venv
source venv/bin/activate  # On Linux/macOS
# On Windows: venv\Scripts\activate
pip install -r requirements.txt

Running from Source

source venv/bin/activate
python src/main.py

Building a Binary

The project includes a build script that uses PyInstaller to create a standalone executable:

Linux / macOS:

source venv/bin/activate
python scripts/build.py

Windows:

venv\Scripts\activate
python scripts/build.py

Options:

• --clean — Remove previous build artifacts before building
• --verbose — Show detailed build output

The resulting binary will be placed in the dist/ directory.

Automated Builds (CI/CD)

GitHub Actions workflows automatically build binaries for all platforms on every push to tagged releases (v*). See the .github/workflows/ directory for details.

Network Requirements

The application requires outbound access to STUN servers:

• UDP/TCP port 3478 (standard STUN)
• TCP port 5349 (STUN over TLS)

Project Structure

NatTypeTester-NG/
├── src/
│   ├── core/          # Settings, configuration
│   ├── transport/     # UDP, TCP, TLS implementations
│   ├── protocol/      # STUN message handling
│   ├── ui/            # PySide6 widgets
│   └── main.py        # Application entry point
├── scripts/
│   └── build.py       # Automated build script
├── tests/             # Unit tests
├── init.sh            # Setup script
└── requirements.txt   # Python dependencies

Linux Desktop Integration

After building the application, you can integrate it into your Linux desktop environment:

# User-level install (no root required)
./install-linux.sh

# System-wide install
sudo ./install-linux.sh system

This installs the binary, desktop entry, and icons to standard XDG locations so NatTypeTester-NG appears in your GNOME, KDE, or other freedesktop-compatible application menu.

License

See LICENSE file for details.