Solved

Obtaining DNS Primary and Secondary Address

Posted on 2002-03-30
3
785 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
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

How your wiki can always stay up-to-date

Quip doubles as a “living” wiki and a project management tool that evolves with your organization. As you finish projects in Quip, the work remains, easily accessible to all team members, new and old.
- Increase transparency
- Onboard new hires faster
- Access from mobile/offline

Join & Write a Comment

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 tutorial you'll learn about bandwidth monitoring with flows and packet sniffing with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're interested in additional methods for monitoring bandwidt…
This video explains how to create simple products associated to Magento configurable product and offers fast way of their generation with Store Manager for Magento tool.

762 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

Need Help in Real-Time?

Connect with top rated Experts

19 Experts available now in Live!

Get 1:1 Help Now