ifc_noproto
data->ifi_noproto = ifp->if_data_counters[ifc_noproto];
data->ifi_noproto += counters[ifc_noproto];
counters_inc(ifp->if_counters, ifc_noproto); /* ? */
counters_inc(ifp->if_counters, ifc_noproto);
#define if_noproto if_data_counters[ifc_noproto]