A Python tool for testing HTTP/3 websites' support for QUIC connection migration by analyzing connection parameters and simulating network changes.

QUIC Connection Migration Tester is a specialized diagnostic tool that helps determine whether an HTTP/3 server properly supports connection migration as defined in RFC 9000. Connection migration is a key feature of QUIC that allows connections to survive network path changes, such as NAT rebinding or switching from Wi-Fi to cellular networks.

• Connection ID Management Testing: Validates server's ability to provide multiple connection IDs
• Network Change Simulation: Simulates network interface changes by modifying local port bindings
• Transport Parameter Analysis: Examines QUIC transport parameters related to migration
• Path Validation Testing: Checks for proper PATH_CHALLENGE/PATH_RESPONSE exchanges
• RFC 9000 Compliance Checking: Verifies adherence to QUIC connection migration standards
• Detailed Logging: Provides comprehensive diagnostic output for troubleshooting

• Python 3.13 or higher
• uv

git clone https://github.com/stackia/quic-migration-tester
cd quic-migration-tester
uv sync

# Install from local directory
uv pip install .

# Or build and install wheel
uv build
uv pip install dist/quic_migration_tester-*.whl

# Run directly with uv
uv run quic-migration-tester https://http3check.net

# Or if installed as package
quic-migration-tester https://http3check.net

# Enable verbose logging for detailed diagnostics
uv run quic-migration-tester https://cloudflare.com --verbose

# Disable certificate verification
uv run quic-migration-tester https://test-server.com --no-verify

• url: Target HTTPS URL to test (required)
• --version: Show program version and exit
• --verbose, -v: Enable verbose logging for detailed output
• --no-verify: Disable TLS certificate verification
• --help, -h: Show help message and exit

# Install with development dependencies
uv sync --dev

# Run code formatting
uv run black .
uv run isort .

# Run type checking
uv run mypy .

# Run linting
uv run flake8 .

# Build source and wheel distributions
uv build

# The built packages will be in the dist/ directory
ls dist/
# quic_migration_tester-0.1.0.tar.gz
# quic_migration_tester-0.1.0-py3-none-any.whl

The tester performs a three-phase connection migration test:

• Establishes QUIC connection with the target server
• Analyzes transport parameters (active_connection_id_limit, disable_active_migration, etc.)
• Collects available connection IDs from the server

• Simulates network interface change by creating a new local socket binding
• Triggers connection ID change using change_connection_id()
• Monitors for PATH_CHALLENGE frames from the server

• Verifies connection remains functional after migration
• Confirms connection state remains CONNECTED
• Performs final connectivity test using ping