unit Unit1;

interface

uses
 Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms,
 Dialogs, StdCtrls, Winsock, ExtCtrls;

const
 MAX_ADAPTER_ADDRESS_LENGTH = 6;

type
 TMacAddress = array[0..MAX_ADAPTER_ADDRESS_LENGTH - 1] of byte;

 TForm1 = class(TForm)
   Button1: TButton;
   procedure Button1Click(Sender: TObject);
 end;

 function SendARP(const DestIP, SrcIP: ULONG;
   pMacAddr: PULONG; var PhyAddrLen: ULONG): DWORD; stdcall; external 'IPHLPAPI.DLL';

var
 Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);

 function GetMAC(Value: TMacAddress; Length: DWORD): String;
 var
   I: Integer;
 begin
   if Length = 0 then Result := '00-00-00-00-00-00' else
   begin
     Result := '';
     for i:= 0 to Length - 2 do
       Result := Result + IntToHex(Value[i], 2) + '-';
     Result := Result + IntToHex(Value[Length-1], 2);
   end;
 end;

var
 DestIP, SrcIP: ULONG;
 pMacAddr: TMacAddress;
 PhyAddrLen: ULONG;
begin
 DestIP := inet_addr('195.182.10.22');
 PhyAddrLen := 6;
 SendArp(DestIP, 0, @pMacAddr, PhyAddrLen);
 Caption := GetMAC(pMacAddr, PhyAddrLen);
end;

end.