Wake On Lan command line application

WakeOnLan.cs

using System;
using System.Diagnostics;
using System.Net;
using System.Net.NetworkInformation;
using System.Net.Sockets;

namespace WakeOnLan
{
    internal class Program
    {
        private static int Main(string[] args)
        {
            var exitCode = MainCore(args);
            if (Debugger.IsAttached) Console.ReadLine();
            return exitCode;
        }

        private static int MainCore(string[] args)
        {
            if (args.Length < 1 || args.Length > 2)
            {
                Console.Error.WriteLine("Error: Wrong number of parameters.\n");
                PrintHelp();
                return -1;
            }

            try
            {
                var mac = PhysicalAddress.Parse(args[0]);
                var endPoint = args.Length == 2 ? IPAddress.Parse(args[1]) : IPAddress.Broadcast;
                SendWakeOnLanPackage(mac, endPoint);
            }
            catch (Exception ex)
            {
                Console.Error.WriteLine("Error: " + ex);
                return -2;
            }
            return 0;
        }

        private static void SendWakeOnLanPackage(PhysicalAddress mac, IPAddress endPoint)
        {
            var client = new UdpClient();

            // WOL packet contains a 6-bytes trailer and 16 times a 6-bytes sequence containing the MAC address.
            var packet = new byte[17 * 6];

            // Trailer of 6 times 0xFF.
            for (int i = 0; i < 6; i++)
            {
                packet[i] = 0xFF;
            }

            // Body of magic packet contains 16 times the MAC address.
            var macBytes = mac.GetAddressBytes();
            for (int i = 1; i <= 16; i++)
            {
                for (int j = 0; j < 6; j++)
                {
                    packet[i * 6 + j] = macBytes[j];
                }
            }

            client.Send(packet, packet.Length, new IPEndPoint(endPoint, 40000));  // Use hard-coded port
        }

        private static void PrintHelp()
        {
            Console.WriteLine($"Usage: {AppDomain.CurrentDomain.SetupInformation.ApplicationName} mac [broadcastAddress]");
            Console.WriteLine("  mac                  The MAC address of the ethernet adapter which is responsible to wake up the device.");
            Console.WriteLine("  [broadcastAddress]   Optional: A subnet-directed broadcast IP address.");
            Console.WriteLine("\nSamples:");
            Console.WriteLine($"  {AppDomain.CurrentDomain.SetupInformation.ApplicationName} 32-A8-F1-5F-F3-C2");
            Console.WriteLine($"  {AppDomain.CurrentDomain.SetupInformation.ApplicationName} 32-A8-F1-5F-F3-C2 192.168.255.255");
        }
    }
}