public function getBinLastIP($dq_host, $cdr_nmask)
 {
     //Takes care of 31 and 32 bit masks.
     if (SubnetCalculator::getHostsTotal($cdr_nmask) > 0) {
         return $bin_last = str_pad(substr(SubnetCalculator::getBinBcast($dq_host, $cdr_nmask), 0, 31), 32, 0);
     } else {
         return 0;
     }
 }