if_lastchange
getmicrotime(&ifp->if_lastchange);
getmicrotime(&ifp->if_lastchange);
getmicrotime(&ifp->if_lastchange);
data->ifi_lastchange = ifp->if_lastchange;
struct timeval if_lastchange; /* [c] last op. state change */
getmicrotime(&sc->sc_if.if_lastchange);
getmicrotime(&sc->sc_if.if_lastchange);
getmicrotime(&sc->sc_if.if_lastchange);