Retrieve and output MAC addresses for all network interfaces of local machine in C#

get_mac_address.cs

using System;
using System.Net.NetworkInformation;
using System.Linq;


namespace Test {
    // Retrieve and output MAC addresses for all network interfaces of local machine
    public class Program {
        static void Main()
        {
            var macAddrs = 
                from nic in NetworkInterface.GetAllNetworkInterfaces()
                select nic.GetPhysicalAddress().ToString();
        
            Console.WriteLine( "Total number of interfaces: {0}",
                               macAddrs.Count() );
            int i = 0;
            foreach( var macAddr in macAddrs ) {
                Console.WriteLine( "{0} = {1}", ++i, macAddr );
            }
        }
    }

    // Retrieve and output MAC addresses for active network interfaces of local machine
    class Program1 {
        static void Main()
        {
            var macAddrs = 
                from nic in NetworkInterface.GetAllNetworkInterfaces()
                where nic.OperationalStatus == OperationalStatus.Up
                select nic.GetPhysicalAddress().ToString();
        
            Console.WriteLine( "Total number of active interfaces: {0}",
                               macAddrs.Count() );
            int i = 0;
            foreach( var macAddr in macAddrs ) {
                Console.WriteLine( "{0} = {1}", ++i, macAddr );
            }
        }
    }
}

get_mac_address.txt

Compile with the following command line:
csc /m:Test.Program test.cs
or 
csc /m:Test.Program1 test.cs