1using System;
2// Be sure to add a reference to System.Management for this class to work properly

3using System.Management;
4
5namespace MacAddress
6{
7    class MACAddress
8    {
9        public string GetMACAddress()
10        {
11            return GetMACAddress("");
12        }
13
14        public string GetMACAddress(string separator)
15        {
16            ManagementClass mc = new ManagementClass("Win32_NetworkAdapterConfiguration");
17            ManagementObjectCollection moc = mc.GetInstances();
18            string MACAddress = String.Empty;
19            foreach (ManagementObject mo in moc)
20            {
21                if (MACAddress == String.Empty) // only return MAC Address from first card 

22                {
23                    if ((bool)mo["IPEnabled"] == true)
24                        MACAddress = mo["MacAddress"].ToString();
25                }
26                mo.Dispose();
27            }
28            MACAddress = MACAddress.Replace(":", separator);
29            return MACAddress;
30        }
31    }
32}
33

MACAddress mac = new MACAddress();
            
string MACAddressString = mac.GetMACAddress(" "); // Separates nodes with spaces
string MACAddressString = mac.GetMACAddress(":"); // Separates nodes with colons
string MACAddressString = mac.GetMACAddress(); // Nodes are not separated
string MACAddressString = mac.GetMACAddress("AnyString"); // Separates nodes with AnyString