ILLF_IPV4
lifr->lifr_flags = ILLF_IPV4;
ill->ill_flags |= ILLF_IPV4;
ill->ill_flags &= ~ILLF_IPV4;
lifr->lifr_flags = (ill->ill_flags & (ILLF_IPV4|ILLF_IPV6));
if (!(ill->ill_flags & (ILLF_IPV4|ILLF_IPV6)))
ill->ill_flags |= ILLF_IPV4;
} else if (ill->ill_flags & ILLF_IPV4) {
ill->ill_flags |= ILLF_IPV4;