def netmasks
      netmask = []
      index = 0
      while index < @datas.count
        index += 1
        netmask << DHCPParser::Conf.get_netmask(@datas["net#{index}"])
      end
      return netmask
    end
def netmasks
      netmask = []
      index = 0
      while index < @datas.count
        index += 1
        netmask << DHCPParser::Conf.get_netmask(@datas["net#{index}"])
      end
      return netmask
    end
Get list netmask