Mega Code Archive
Trace Route to IP Address (Like Windows TRACERT)
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Title: Trace Route to IP Address (Like Windows TRACERT)
Question: This class implements a trace route to target ip address similar to the Windows command line TraceRt. The class is a lot faster than the Windows command as we do not resolve names using DNS and only ping once as opposed to four times.
The results are returned in a passed TStrings structure in semi-colon delimited fields IP; TIME; TTL; STATUS.
Setable properties are IcmpTimeOut (Default 5000ms) and IcmpMaxHops (Default 40)
Code Example
procedure TForm1.Button1Click(Sender: TObject);
var RT : TTraceRoute;
begin
RT := TTraceRoute.Create;
RT.Trace('192.168.5.12',ListBox1.Items);
RT.Free;
end;
Output Example
196.11.175.6;0;255;OK
196.11.180.62;94;254;OK
192.168.5.12;109;126;OK
Answer:
unit TraceRt;
interface
// ===========================================================================
// TRACEROUTE Class
// Mike Heydon Dec 2003
//
// Method
// Trace(IpAddress : string; ResultList : TStrings)
// Returns semi-colon delimited list of ip routes to target
// format .. IP ADDRESS; PING TIME MS; TIME TO LIVE; STATUS
//
// Properties
// IcmpTimeOut : integer (Default = 5000ms)
// IcmpMaxHops : integer (Default = 40)
// ===========================================================================
uses Forms, Windows, Classes, SysUtils, IdIcmpClient;
type
TTraceRoute = class(TObject)
protected
procedure ProcessResponse(Status : TReplyStatus);
procedure AddRoute(AResponseTime : DWORD;
AStatus: TReplyStatus; const AInfo: string );
private
FIcmpTimeOut,
FIcmpMaxHops : integer;
FResults : TStringList;
FICMP : TIdIcmpClient;
FPingStart : cardinal;
FCurrentTTL : integer;
procedure PingTarget;
public
constructor Create;
procedure Trace(const AIpAddress : string; AResultList : TStrings);
property IcmpTimeOut : integer read FIcmpTimeOut write FIcmpTimeOut;
property IcmpMaxHops : integer read FIcmpMaxHops write FIcmpMaxHops;
end;
// ---------------------------------------------------------------------------
implementation
// ========================================
// Create the class and set defaults
// ========================================
constructor TTraceRoute.Create;
begin
IcmpTimeOut := 5000;
IcmpMaxHops := 40;
end;
// =============================================
// Use Indy component to ping hops to target
// =============================================
procedure TTraceRoute.PingTarget;
var wOldMode : DWORD;
begin
Application.ProcessMessages;
inc(FCurrentTTL);
if FCurrentTTL FICMP.TTL := FCurrentTTL;
FICMP.ReceiveTimeout := FIcmpTimeOut;
FPingStart := GetTickCount;
wOldMode := SetErrorMode(SEM_FAILCRITICALERRORS);
try
FICMP.Ping;
ProcessResponse(FICMP.ReplyStatus);
except
FResults.Add('0.0.0.0;0;0;ERROR');
end;
SetErrorMode(wOldMode);
end
else
FResults.Add('0.0.0.0;0;0;MAX HOPS EXCEEDED');
end;
// ============================================================
// Add the ping reply status data to the returned stringlist
// ============================================================
procedure TTraceRoute.AddRoute(AResponseTime : DWORD;
AStatus: TReplyStatus;
const AInfo: string );
begin
FResults.Add(AStatus.FromIPAddress + ';' +
IntToStr(GetTickCount - AResponseTime) + ';' +
IntToStr(AStatus.TimeToLive) + ';' + AInfo);
end;
// ============================================================
// Process the ping reply status record and add to stringlist
// ============================================================
procedure TTraceRoute.ProcessResponse(Status : TReplyStatus);
begin
case Status.ReplyStatusType of
// Last Leg - Terminate Trace
rsECHO : AddRoute(FPingStart,Status,'OK');
// More Hops to go - Continue Pinging
rsErrorTTLExceeded : begin
AddRoute(FPingStart,Status,'OK');
PingTarget;
end;
// Error conditions - Terminate Trace
rsTimeOut : AddRoute(FPingStart,Status,'TIMEOUT');
rsErrorUnreachable : AddRoute(FPingStart,Status,'UNREACHABLE');
rsError : AddRoute(FPingStart,Status,'ERROR');
end;
end;
// ======================================================
// Trace route to target IP address
// Results returned in semi-colon delimited stringlist
// IP; TIME MS; TIME TO LIVE; STATUS
// ======================================================
procedure TTraceRoute.Trace(const AIpAddress : string;
AResultList : TStrings);
begin
FICMP := TIdIcmpClient.Create(nil);
FICMP.Host := AIpAddress;
FResults := TStringList(AResultList);
FResults.Clear;
FCurrentTTL := 0;
PingTarget;
FICMP.Free;
end;
{eof}
end.
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