Если можете помогите.

unit main;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, ExtCtrls, StdCtrls, IdBaseComponent, IdComponent, IdRawBase,
IdRawClient, IdIcmpClient;

type
TForm1 = class(TForm)
Panel1: TPanel;
Label1: TLabel;
Label2: TLabel;
Edit1: TEdit;
Edit2: TEdit;
ListBox1: TListBox;
Button1: TButton;
IdIcmpClient1: TIdIcmpClient;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var
a11,a12,a13,a14,a21,a22,a23,a24:Integer;
i:Integer;
c1,c2:Cardinal;
S:String;
CurrentStr: string;
begin
CurrentStr:='1';
ListBox1.Clear;
S:=Edit1.text;
a11:=StrToInt(Copy(s,1,pos('.',s)-1));
Delete(s,1,pos('.',s));
a12:=StrToInt(Copy(s,1,pos('.',s)-1));
Delete(s,1,pos('.',s));
a13:=StrToInt(Copy(s,1,pos('.',s)-1));
Delete(s,1,pos('.',s));
a14:=StrToInt(Copy(s,1,Length(s)));
S:=Edit2.text;
a21:=StrToInt(Copy(s,1,pos('.',s)-1));
Delete(s,1,pos('.',s));
a22:=StrToInt(Copy(s,1,pos('.',s)-1));
Delete(s,1,pos('.',s));
a23:=StrToInt(Copy(s,1,pos('.',s)-1));
Delete(s,1,pos('.',s));
a24:=StrToInt(Copy(s,1,Length(s)));
c1:=a11 shl 24 + a12 shl 16 + a13 shl 8 + a14;
c2:=a21 shl 24 + a22 shl 16 + a23 shl 8 + a24;

for i:=c1 to c2 do
IdIcmpClient1.Host:=IntToStr(i);
IdIcmpClient1.Ping;
if IdIcmpClient1.ReplyStatus.TimeToLive <>0 then
CurrentStr:=IdIcmpClient1.Host + ' - ok'
else
CurrentStr:=IdIcmpClient1.Host + ' - down';
ListBox1.items.Add(CurrentStr);

end;

end.

Вроде все правильно ни пошет при выполнение то что Хост не найден.