pystun3

Discover NAT type using STUN protocol

TLDR

Check NAT type

$ pystun3

Use specific STUN server

$ pystun3 -H [stun.example.com]

Specify source port

$ pystun3 -p [54320]

Use specific interface

$ pystun3 -i [192.168.1.100]

Enable debug logging

$ pystun3 -d

Specify STUN server port

$ pystun3 -H [stun.example.com] -P [3478]

SYNOPSIS

pystun3 [-H server] [-p port] [-i ip] [options]

pystun3 is a STUN (Session Traversal Utilities for NAT) client that discovers the type of NAT between a host and the internet. It communicates with a STUN server to determine the NAT classification (full cone, restricted cone, port restricted, or symmetric) and reports the external IP address and mapped port.Understanding NAT type is essential for configuring VoIP, video conferencing, and peer-to-peer applications that require direct connections between hosts. The tool can target specific STUN servers and bind to particular network interfaces.

PARAMETERS

-H STUNHOST, **--host** STUNHOST

STUN server hostname.

-P STUNPORT, **--host-port** STUNPORT

STUN server port (default: 3478).

-p SOURCEPORT, **--port** SOURCEPORT

Source port to listen on (default: 54320).

-i SOURCEIP, **--interface** SOURCEIP

Network interface for client (default: 0.0.0.0).

-d, --debug

Enable debug logging.

--version

Show program version.

CAVEATS

Requires network access. STUN server must be reachable. NAT types vary.

HISTORY

pystun3 is a Python 3 port of pystun, implementing STUN (Session Traversal Utilities for NAT) client functionality.