如何知道在"局域网"内的某IP的机器的是否开机?

Question

一个局域网内有20多台机器，如何知道某IP的机器是否开机？用ping的方法我已经知道了，如何用Delphi程序实现？？
    用‘机器名’检测我已实现，但是用IP检测的话速度很慢，效率太低，这我确实有点想不通，“机器名”不是还要转成IP吗，为什么反而还慢了？？？？

Answer 1

用Indy控件：Indy Clients面板下面的IdEcho。

Answer 2

uses
WinSock;Function sendarp(ipaddr:ulong;
temp:dword;
ulmacaddr:pointer;
ulmacaddrleng:pointer) : DWord; StdCall; External 'Iphlpapi.dll' Name 'SendARP';procedure TForm1.Button1Click(Sender: TObject);
var
myip:ulong;
mymac:array[0..5] of byte;
mymaclength:ulong;
r:integer;
begin
myip:=inet_addr(PChar('192.168.6.180'));
mymaclength:=length(mymac);
r:=sendarp(myip,0,@mymac,@mymaclength);
label1.caption:='errorcode:'+inttostr(r);
label2.caption:=format('%2.2x:%2.2x:%2.2x:%2.2x:%2.2x:%2.2x',[mymac[0],mymac[1],mymac[2],mymac[3],mymac[4],mymac[5]]);
end;上面的代码看r就行了，r=0表示成功把这个ip地址转为mac，也就是这个ip开机了，不是0就没有开机
速度比ping快多了
不过不同网段的好像不可以这样

Answer 3

struct sockaddr_in stationaddr;
stationaddr.sin_family = AF_INET;
stationaddr.sin_port = htons(LocalListenPort);
stationaddr.sin_addr.S_un.S_addr = htonl(m_stationinfo.IP);
HOSTENT *pResult = gethostbyaddr((const char *)&(stationaddr.sin_addr),4,AF_INET);
if(pResult==NULL && !bManual)
{
int nErrorCode = WSAGetLastError(); }
else //网络正常
{ }这是VC的
你改一改吧

Answer 4

Angel:为什么返回总是r<>0?   
   如：156.20.23.123
   返回：errorcode:87
       40:00:E8:09:43:00
　　　　

Answer 5

同网段？ 
还有156.20.23.123 是lan里面的ip？这个是公网的吧，要用lan内部ip
如192.168.0.xx
我在我的lan试过的

Answer 6

看自带例子，Indy　有一个实现Ping 的操作

Answer 7

uses winsock
以下是转贴：
     PIPOptionInformation = ^TIPOptionInformation;
     TIPOptionInformation = packed record
          TTL: Byte;
          TOS: Byte;
          Flags: Byte;
          OptionsSize: Byte;
          OptionsData: PChar;
     end;     PIcmpEchoReply = ^TIcmpEchoReply;
     TIcmpEchoReply = packed record
         Address: DWORD;
         Status: DWORD;
         RTT: DWORD;
         DataSize: Word;
         Reserved: Word;
         Data: Pointer;
         Options: TIPOptionInformation;
     end;    TIcmpCreateFile = function : THandle;stdcall;
    TIcmpCloseHandle = function(IcmpHandle : THandle):Boolean;stdcall;
    TIcmpSendEcho = function(IcmpHandle : THandle;DestinationAddress : DWord;
                      ResquestData : Pointer;RequestSize : Word;
                      RequestOption : PIPOptionInformation;
                      ReplyBuffer  : Pointer; ReplySize : DWord;
                      TimeOut : DWord) : DWord;stdcall;

Answer 8

TMyPing = class(TForm)
    ExeBtn: TBitBtn;
    Panel1: TPanel;
    PingEdit: TEdit;
    StatusShow: TMemo;
    procedure ExeBtnClick(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
    hICMP: THANDLE;
    IcmpCreateFile : TIcmpCreateFile;
    IcmpCloseHandle: TIcmpCloseHandle;
    IcmpSendEcho: TIcmpSendEcho;
  public
    { Public declarations }
  end;var
  MyPing: TMyPing;implementation{$R *.dfm}procedure TMyPing.FormCreate(Sender: TObject);
var
  WSAData : TWSAData;
  hICMPdll : HMODULE;
begin
  WSAStartup($101,WSAData);
  //Load the icmp.dll stuff
  hICMPdll := LoadLibrary('icmp.dll');
  @ICMPCreateFile := GetProcAddress(hICMPdll,'IcmpCreateFile');
  @IcmpCloseHandle := GetProcAddress(hICMPdll, 'IcmpCloseHandle');
  @IcmpSendEcho := GetProcAddress(hICMPdll, 'IcmpSendEcho');  hICMP := IcmpCreateFile;
  StatusShow.Text := '';
  StatusShow.Lines.Add(' 目的IP地址      字节数    返回时间(毫秒)');
end;procedure TMyPing.ExeBtnClick(Sender: TObject);
var
  IPOpt:TIPOptionInformation;// IP Options for packet to send
  FIPAddress:DWORD;
  pReqData,pRevData:PChar;
  pIPE:PIcmpEchoReply;// ICMP Echo reply buffer
  FSize: DWORD;
  MyString:string;
  FTimeOut:DWORD;
  BufferSize:DWORD;
  cnt : integer;
begin
  if PingEdit.Text <> '' then
  begin
    FIPAddress := inet_addr(PChar(PingEdit.Text));
    FSize := 40;
    BufferSize := SizeOf(TICMPEchoReply) + FSize;
    GetMem(pRevData,FSize);
    GetMem(pIPE,BufferSize);
    FillChar(pIPE^, SizeOf(pIPE^), 0);
    pIPE^.Data := pRevData;
    MyString := 'Hello,World';
    pReqData := PChar(MyString);
    FillChar(IPOpt, Sizeof(IPOpt), 0);
    IPOpt.TTL := 64;
    FTimeOut := 1000;
    for cnt := 0 to 10 do
    begin
      try
        IcmpSendEcho(hICMP, FIPAddress, pReqData, Length(MyString),@IPOpt, pIPE, BufferSize, FTimeOut);
        if pReqData^ = pIPE^.Options.OptionsData^ then
          StatusShow.Lines.Add('  '+ PChar(PingEdit.Text) + '          ' + IntToStr(pIPE^.DataSize)
              + '             ' +IntToStr(pIPE^.RTT));
      except
        StatusShow.Lines.Add('Cant resolve host!');
        FreeMem(pRevData);
        FreeMem(pIPE);
        Exit;
      end;
    end;
    FreeMem(pRevData);
    FreeMem(pIPE);
    ICMPCloseHandle(hICMP);
end;end;
end.