#40 Cannot send IPv6 UDP multicast on MacOSX platform

[Huub Eikens]

When using TclUDP version 1.0.10 I'm not able to send IPv6 UDP multicast on MacOSX platform.

Some notes:
- Receiving IPv6 UDP multicast on MacOSX works fine.
- This problem does not occur on other platforms (Linux, Windows).
- Sending (and receiving) IPv4 UDP multicast on MacOSX works fine.

The attached tcl script can be used to re-produce the problem.

When analysing the problem, I see that the function udpOutput() is called and that the IPv6 UDP multicast package is sent successfully by the function sendto(). When using a network sniffer, I don't see the send IPv6 packages.