In order to set the scope id, we will need to know the interface index
before sending, in some cases.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>
It is safer and more correct to clear the addresses before use. The IPv6
fields flowinfo and scope_id in particular should not be set to random
values from the stack.
Signed-off-by: Richard Cochran <richardcochran@gmail.com>