public function delete()
 {
     if ($this->getNetworkinterfaceId() != 0) {
         //delete all assigned ip addresses
         $iplist = new Iplist($this->getNetworkinterfaceId());
         $iplist->delete();
         //delete all interface crawl data
         $networkinterfacestatuslist = new NetworkinterfaceStatusList($this->getNetworkinterfaceId());
         $networkinterfacestatuslist->delete();
         //delete interface
         try {
             $stmt = DB::getInstance()->prepare("DELETE FROM interfaces WHERE id=?");
             $stmt->execute(array($this->getNetworkinterfaceId()));
             return $stmt->rowCount();
         } catch (PDOException $e) {
             echo $e->getMessage();
             echo $e->getTraceAsString();
         }
     }
     return false;
 }