RTF_MULTICAST
rt->rt_flags |= RTF_MULTICAST;
if (!(rt->rt_flags & (RTF_HOST | RTF_CLONING | RTF_MULTICAST)))
(RTF_MULTICAST | RTF_BROADCAST | RTF_WASCLONED)) == 0)
rt->rt_flags |= RTF_MULTICAST;
if (!(rt->rt_flags & (RTF_HOST | RTF_CLONING | RTF_MULTICAST))) {