for multicast setsockopt, use 0.0.0.0/8 to specify interface index following RFC1724 section 3.3.  suggested by Dave Thaler.
for multicast setsockopt, use 0.0.0.0/8 to specify interface index
following RFC1724 section 3.3.  suggested by Dave Thaler.

MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame,MarginC/kame