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How To Get IP Address Of A Machine

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1 Feb 2001 829.3K   96   62
Tip on how to use DNS class and get IP address of a machine

Introduction

This article is not a technical overview or large discussion. It is like a collection of tips on how you can get the IP address or host name of a machine. In the Win32 API this could be accomplished using the NetWork API. And this is still true in the .NET framework. The only difference is finding and understanding what namespace and class to use to accomplish this task. In the .NET framework the NetWork API is available in the System.Net namespace. The DNS class in the System.Net namespace can be used to get the hostname of a machine or get the IP address if the hostname is already known. The DNS class provides a simple domain name resolution functionality. The DNS class is a static class that provides access to information from the Internet Domain Name System (DNS). The information returned includes multiple IP addresses and aliases if the host specified has more than one entry in the DNS database. The list is returned as a collection or an array of IPAddress objects. The following section is the code that shows how to obtain the IP address for a given host name.

DNSUtility Code

namespace NKUtilities 
{
    using System;
    using System.Net;
    
    public class DNSUtility
    {
        public static int Main (string [] args)
        {
        
          String strHostName = new String ("");
          if (args.Length == 0)
          {
              // Getting Ip address of local machine...
              // First get the host name of local machine.
              strHostName = DNS.GetHostName ();
              Console.WriteLine ("Local Machine's Host Name: " +  strHostName);
          }
          else
          {
              strHostName = args[0];
          }
          
          // Then using host name, get the IP address list..
          IPHostEntry ipEntry = DNS.GetHostByName (strHostName);
          IPAddress [] addr = ipEntry.AddressList;
          
          for (int i = 0; i < addr.Length; i++)
          {
              Console.WriteLine ("IP Address {0}: {1} ", i, addr[i].ToString ());
          }
          return 0;
        }    
     }
}

What The Code Does

If you want to obtain the hostname of the local machine, then call the GetHostName method without a parameter. Then use the resulting hostname as a parameter to the GetHostByName method to get the list of IPAddresses that may be associated with the hostname. Then iterate through the collection of addresses to write out the IP Addresses associated with the hostname.

Reminders

Make sure that you include the System.Net namespace in your code; otherwise the compiler will not know where to look for the DNS class. Also when you use VisualStudio.NET for creating the project, make sure that you have the System.NET.Dll in your reference list. For more information on the DNS class and System.Net namespace, please refer to the online documentation for the .NET SDK.

License

This article has no explicit license attached to it but may contain usage terms in the article text or the download files themselves. If in doubt please contact the author via the discussion board below.

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Comments and Discussions

 
GeneralThis is very good article. Pin
Jayesh Sorathia7-Aug-12 21:55
Jayesh Sorathia7-Aug-12 21:55 
QuestionConsole closing Pin
Arjun Menon U.K30-Jun-12 2:36
Arjun Menon U.K30-Jun-12 2:36 
AnswerRe: Console closing Pin
jleol16-Sep-16 2:05
jleol16-Sep-16 2:05 
GeneralMy vote of 2 Pin
hlsnnet2-Apr-12 20:52
hlsnnet2-Apr-12 20:52 
Questionreferences of your article Pin
Md. Marufuzzaman25-Dec-11 7:41
professionalMd. Marufuzzaman25-Dec-11 7:41 
GeneralInetAddress Pin
Prerna Sancheti6-May-11 5:00
Prerna Sancheti6-May-11 5:00 
GeneralMy vote of 2 Pin
Ravi Sant6-Jan-11 0:34
Ravi Sant6-Jan-11 0:34 
GeneralMy vote of 3 Pin
Libin Jose chemperi6-Dec-10 23:15
Libin Jose chemperi6-Dec-10 23:15 
GeneralMy vote of 1 Pin
Jörgen Sigvardsson9-Jun-09 20:11
Jörgen Sigvardsson9-Jun-09 20:11 
GeneralRe: My vote of 1 Pin
PRMan!!!24-Sep-09 8:26
PRMan!!!24-Sep-09 8:26 
And the right way is?
GeneralRe: My vote of 1 PinPopular
Sabrina Hope21-May-10 6:07
Sabrina Hope21-May-10 6:07 
AnswerRe: My vote of 1 Pin
Kenneth McKnight15-Jun-10 21:41
Kenneth McKnight15-Jun-10 21:41 
General[newbie] Pin
jon-8029-Mar-09 4:05
professionaljon-8029-Mar-09 4:05 
GeneralRe: [newbie] Pin
ByteBlocks29-Mar-09 7:27
ByteBlocks29-Mar-09 7:27 
GeneralRe: [newbie] [modified] Pin
jon-8030-Mar-09 12:10
professionaljon-8030-Mar-09 12:10 
GeneralRe: [newbie] Pin
ByteBlocks30-Mar-09 14:00
ByteBlocks30-Mar-09 14:00 
Generalhello Pin
jr_jamesrobert016-Jun-08 11:45
jr_jamesrobert016-Jun-08 11:45 
Questionhow how u there Pin
jr_jamesrobert016-Jun-08 7:28
jr_jamesrobert016-Jun-08 7:28 
QuestionWhat I'd really like to see is... Pin
mycal27-Sep-07 8:24
mycal27-Sep-07 8:24 
GeneralIPv6 (::1) issue with this code. PinPopular
durkpurk28-Jul-07 1:03
durkpurk28-Jul-07 1:03 
GeneralRe: IPv6 (::1) issue with this code. Pin
Monir Sabbagh21-Apr-09 23:16
Monir Sabbagh21-Apr-09 23:16 
GeneralRe: IPv6 (::1) issue with this code. Pin
IvanGB0016-Jul-12 3:03
IvanGB0016-Jul-12 3:03 
Generalquestion in getting system information Pin
varghesh17-Mar-07 21:18
varghesh17-Mar-07 21:18 
GeneralGet all IPAddress in the network Pin
Wakwak Chimera3-Jan-07 19:25
Wakwak Chimera3-Jan-07 19:25 
QuestionHow To Get IP Address &amp; MAC address Of (Barcode Printer) of the Network? Pin
Jan Palmer3-Jan-07 18:46
Jan Palmer3-Jan-07 18:46 

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