I've found an error when dealing with torrent-Files,
which contain only an IPv6 tracker URL, (i.e.
The program recognises, that it's an IPv6-URL and also
connects to the tracker via IPv6, doing the normal
announce. However the tracker only gets the IPv6-adress
of the client and notes it. The client on the other
hand is only listening on an IPv4-socket and therefore
it will never get any incoming connections.
The problem could be solved in three ways:
a.) Don't even announce to IPv6-trackers, and give the
user a message to inform him about the problem.
b.) Try to determine an existent IPv4 adress and
automatically add an ip= parameter to the tracker request.
c.) Add proper IPv6 support.