TereStun is a very simple unitility to determine external IPv4 address and source port over NAT, using Teredo protocol.
In other words, this is a STUN-like client over Teredo.
$ ./terestun.pyz --help
usage: Teredo STUN [-h] [-s SERVER] [-p PORT] [--ip-only] [--port-only]
Get IPv4 address and source port over Teredo network
options:
-h, --help show this help message and exit
-s SERVER, --server SERVER
Teredo server
-p PORT, --port PORT Source port to use
--ip-only Show only IPv4 address, without port
--port-only Show only source port, without IPv4 address
$ ./terestun.pyz
142.251.36.110:44254