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How To Get The MAC Addres From an IP Address or Computername inside a Webservice

I am writing a webservice which takes in a MAC address, IP addres, or computername. I check the string and convert IP or Computername to the MAC address.

For IP address, I tried to spawn an EXE (NBTSTAT -a IP_Address) so I could parse the output.
For computername, I was going to ping to get the IP address and then do the above step.

However, calling an EXE from a webservice doesn't seem to be as easy as doing it from a console app.
i.e. The code executes but there is nothing being sent to standard output and no error.

What would be the best way to accomplish this?
Call an EXE from a webservice?
Or, is there something in the C# library that will allow me to turn a computername or an IP address into a MAC address?

Thanks!

john-at-7fff

Just out of curiosity, are you doing this in order to get a unique identifier?

Also: One IP address can have multiple Mac addresses if the machines are clustered or there's load distribution hardware in front of the machine.

winterminute

ASKER

Nope, I am using an application which requires me to work with MAC addresses, but rather than force users to know their MAC address, I'll take a computer name or IP address and work from there.

john-at-7fff

Well, on Windows you can get the MAC address for your OWN machine through a NETBIOS call.

For the flavor of this, here's a VB example that you might be able to adapt to C#:

http://custom.programming-in.net/articles/art9-1.asp?f=HeapAlloc

Here's another thing you might look at:

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/iphlp/iphlp/getadaptersinfo.asp
http://msdn.microsoft.com/library/en-us/iphlp/iphlp/ip_adapter_info.asp?frame=true

john-at-7fff

I see where you're going with this. You want to do an arp -a programmatically. This is what you want:

http://www.codeguru.com/Cpp/I-N/internet/internetprotocolip/article.php/c6153/

winterminute

ASKER

Yeah, so can you translate that into C#?

john-at-7fff

More:

http://www.codeguru.com/Cpp/I-N/network/basicnetworkoperations/article.php/c6861/

Unfortunately you'll have to adapt it to C#, or link in some C++.

john-at-7fff

No, but now that you have the C++ code, it may be that someone else can contribute the translation, or strategy to use the C++ module from you C# program . . .

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int_20h

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winterminute

ASKER

I think that System.Net.Dns has something for me.
GetHostByAddress and GetHostByName both return a "System.Net.IPHostEntry" instance.
I looked through that object and didn't see the MAC address listed, but I am still looking....

john-at-7fff

There you go -- see what int_20h sez.

winterminute

ASKER

int_20h >> There doesn't seem to be a parse method for IPAddress?

int_20h

From the doc, there is a parse method in IPAddress:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfSystemNetIPAddressClassParseTopic.asp

Are you using .NET Framework 1.1?

winterminute

ASKER

Yes, I am using 1.1. Let me look into that article...

winterminute

ASKER

int_20h >> That worked perfectly! Thanks! I already awarded the points, but if you can point me two a web resources which talks more about the System.Net namespace and the various objects, I woudl appercaite it.

If not, thanks again for your help!

john-at-7fff

Glad you found that C# code for SendARP!

int_20h

Thanks winterminute! Here is a URL that has lots of Networking articles you might want to read!
http://www.c-sharpcorner.com/Networking.asp

Enjoy!!!

cezart

An other way is WMI. This is a snippet (I hope understandable):

ManagementPath path = new ManagementPath("\\\\" + "xxx.xxx.xxx.xxx" + "\\root\\cimv2");
ConnectionOptions opt = new ConnectionOptions();
opt.Username = txtUser.Text;
opt.Password = txtPassword.Text;
System.Management.ManagementScope mstest = new ManagementScope(path, opt);
System.Management.ManagementScope ms = new ManagementScope(path, opt);
ms.Options.EnablePrivileges = true;
for(int i = 0; i <= 16; i++)
{
      string queryMAC = "select MACAddress, description from Win32_NetworkAdapter where                         Manufacturer <> 'Microsoft' and Manufacturer <> NULL and DeviceID=" + "'" + i + "'";
      System.Management.ObjectQuery oqMAC = new ObjectQuery(queryMAC);
      ManagementObjectSearcher query1MAC = new ManagementObjectSearcher(ms, oqMAC) ;
      ManagementObjectCollection queryCollection1MAC = query1MAC.Get();
      foreach(ManagementObject mo in queryCollection1MAC)
      {
       if(mo["MACAddress"] == null)
            {}
            else
            {
                  mac = mo["MACAddress"].ToString();
                  nic = mo["description"].ToString();
                  item.SubItems.Add(mac);
                  item.SubItems.Add(nic);
            }

            Cursor.Current = Cursors.WaitCursor;

            }
      }
}