Understanding MAC Addresses

[Mike Hildner]

I want to use the MAC address for hardware authentication purposes. I found this (slightly modified) code on the web:

        private void btnGetMACAddress_Click(object sender, System.EventArgs e)
        {
            ManagementObjectSearcher query = null; 
            ManagementObjectCollection queryCollection = null; 

            try 
            { 
                query = new ManagementObjectSearcher("SELECT * FROM Win32_NetworkAdapterConfiguration") ; 
                queryCollection = query.Get(); 

                foreach( ManagementObject mo in queryCollection ) 
                { 
                    if(mo["MacAddress"] != null) 
                    { 
                        MessageBox.Show(mo["MacAddress"].ToString()); 
                    } 
                } 
            } 
            catch(Exception ex) 
            { 
                MessageBox.Show(ex.Source); 
                MessageBox.Show(ex.Message); 
            } 
        
        } 

Now, that code seems to work just fine. But, it shows 5 MAC addresses on my machine. In my network connections, I have four "LAN or High-Speed Internet" connections. ipconfig /all shows me two connections (the two that are currently enabled). getmac from a command line shows me four connections, two that are enabled (so I get the MAC addresses for them).

Anyone know where the fifth MAC address is coming from?

Thanks,
Mike