IEE_WANT_MCAST
if ((sc->sc_flags & IEE_WANT_MCAST) != 0) {
sc->sc_flags |= IEE_WANT_MCAST;
sc->sc_flags &= ~IEE_WANT_MCAST;
if ((sc->sc_flags & IEE_WANT_MCAST) == 0)
sc->sc_flags &= ~IEE_WANT_MCAST;