Solved

Obtaining DNS Primary and Secondary Address

Posted on 2002-03-30
3
795 Views
Last Modified: 2007-11-27
I need to know how to obtain both the primary and secondary DNS addresses from a machine currently connected to the net.

Assume that I will already know if a connection is present, I just need to obtain the DNS numbers and assign them to a String variable in the proper Quad format.
0
Comment
Question by:quantum2
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
3 Comments
 
LVL 14

Expert Comment

by:DragonSlayer
ID: 6909712
I don't know if this is the proper format, but if you just need to obtain it from the registry, here goes: (Win2K)

Navigate to HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters\Adapters

Loop through the name of the keys to obtain the network interfaces you have (they are enclosed in braces, {}, eg {E0149FCC-34D2-4158-884B-A06F3B6F0F8E})

Let's say you managed to get {E0149FCC-34D2-4158-884B-A06F3B6F0F8E} (that is, HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters\Adapters{E0149FCC-34D2-4158-884B-A06F3B6F0F8E}), remember the key, then navigate to HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters\Interfaces\YourKeyName, eg. HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\Tcpip\Parameters\Interfaces\{E0149FCC-34D2-4158-884B-A06F3B6F0F8E}

Open the key, then read the value for NameServer. The DNS servers are separated by a comma.


HTH
DragonSlayer
0
 
LVL 11

Accepted Solution

by:
shaneholmes earned 100 total points
ID: 6911405
Try this function "GetDNSIP"


 function GetDnsIp : string;
 var
   Output        : TStringList;
   DnsIp,
   CmdLine       : string;
 begin
   CmdLine := GetIpCfgExePath;
   if CmdLine <> '' then
   begin
     Output := TStringList.Create;
     try
       case GetBasicOsType of
         VER_PLATFORM_WIN32_WINDOWS :
         begin
           if ExecAndGetConsoleOutput (CmdLine, Output) then
             Output.LoadFromFile (GetIpCfg9xOutPath);
         end;
         else
           ExecAndGetConsoleOutput (CmdLine, Output);
       end;
       if GetDnsIpFromIpCfgOut (Output, DnsIp) then
         Result := DnsIp
       else
       begin
         //
         // Attempt to locate via registry
         //
         Result := GetDnsIpFromReg;
       end;
     finally
       Output.Free;
     end;
   end;
 end;

 

function GetDnsIpFromReg : string;
 var
   OpenKey       : HKEY;
   Vn,
   SubKey        : PChar;
   DataType,
   DataSize      : integer;
   Temp          : array [0..2048] of char;
 begin
   Result := '';
   SubKey := '';
   Vn := '';
   case GetBasicOsType of
     VER_PLATFORM_WIN32_WINDOWS  :
     begin
       SubKey := REG_9X_NAMESERVER_PATH;
      Vn := REG_9X_NAMESERVER;
     end;
     VER_PLATFORM_WIN32_NT       :
     begin
       SubKey := REG_NT_NAMESERVER_PATH;
       Vn := REG_NT_NAMESERVER;
     end;
   end;
   if RegOpenKeyEx (HKEY_LOCAL_MACHINE, SubKey, REG_OPTION_NON_VOLATILE,
     KEY_READ, OpenKey) = ERROR_SUCCESS then
   begin
     DataType := REG_SZ;
     DataSize := SizeOf(Temp);
     if RegQueryValueEx (OpenKey, Vn, nil, @DataType, @Temp,
       @DataSize) = ERROR_SUCCESS then
       Result := string(Temp);
     RegCloseKey (OpenKey);
   end;
 end;

function GetDnsIpFromIpCfgOut (const Output : TStringList;
   var DnsIp : string) : boolean;
 var
   i     : integer;
 begin
   Result := FALSE;
   if Output.Count >= 1 then
     for i := 0 to Output.Count - 1 do
     begin
       if Pos(IPCFG_DNS_SERVER_LINE, Output[i]) > 0 then
       begin
         DnsIp := Trim(Copy (Output[i], Pos(':', Output[i])+1,
           Length(Output[i])));
         Result := LooksLikeIp (DnsIp);
       end;
     end;
 end;
0
 
LVL 1

Author Comment

by:quantum2
ID: 6942364
Thanks a bunch...
Just what I was looking for. I really apprecaite the help.

Quantum2
0

Featured Post

[Live Webinar] The Cloud Skills Gap

As Cloud technologies come of age, business leaders grapple with the impact it has on their team's skills and the gap associated with the use of a cloud platform.

Join experts from 451 Research and Concerto Cloud Services on July 27th where we will examine fact and fiction.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Introduction I have seen many questions in this Delphi topic area where queries in threads are needed or suggested. I know bumped into a similar need. This article will address some of the concepts when dealing with a multithreaded delphi database…
In my programming career I have only very rarely run into situations where operator overloading would be of any use in my work.  Normally those situations involved math with either overly large numbers (hundreds of thousands of digits or accuracy re…
In this video, viewers are given an introduction to using the Windows 10 Snipping Tool, how to quickly locate it when it's needed and also how make it always available with a single click of a mouse button, by pinning it to the Desktop Task Bar. Int…
This tutorial will teach you the special effect of super speed similar to the fictional character Wally West aka "The Flash" After Shake : http://www.videocopilot.net/presets/after_shake/ All lightning effects with instructions : http://www.mediaf…
Suggested Courses
Course of the Month5 days, 9 hours left to enroll

626 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question