Local devices

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

class Program
{
    static void Main()
    {
        foreach (NetworkInterface interfac in NetworkInterface.GetAllNetworkInterfaces())
        {
            if (interfac.OperationalStatus == OperationalStatus.Up)
            {
                Console.WriteLine("Имя интерфейса: " + interfac.Name);
                Console.Write("IPv4-адреса:");

                // Получаем IPv4-адреса для текущего интерфейса
                foreach (UnicastIPAddressInformation ip in interfac.GetIPProperties().UnicastAddresses)
                {
                    if (ip.Address.AddressFamily == System.Net.Sockets.AddressFamily.InterNetwork) // Проверяем, что это IPv4-адрес
                    {
                        Console.WriteLine("  " + ip.Address.ToString());
                        Console.WriteLine("Маска подсети: " + ip.IPv4Mask.ToString());
                    }
                }

                Console.WriteLine();
            }
        }

        Console.Write("\nВведите IP-адрес сети для сканирования: ");
        string? ipAddress = Console.ReadLine();

        Console.Write("Введите маску подсети: ");
        string? maskAddress = Console.ReadLine();
        Console.WriteLine();

        IPAddress ipSearch;
        IPAddress maskSearch;
        if (IPAddress.TryParse(ipAddress, out ipSearch) && IPAddress.TryParse(maskAddress, out maskSearch))
        {
            ScanNetwork(ipSearch, maskSearch);
        }
        else
        {
            Console.WriteLine("Неверный формат IP-адреса или маски подсети.");
        }

        Console.WriteLine("Сканирование завершено.");
        Console.ReadLine();
    }

    static void ScanNetwork(IPAddress ip, IPAddress mask)
    {
        IPAddress ipAddress = GetNetworkAddress(ip, mask);

        int loopCount = CalculateLoopCount(mask);

        switch (loopCount)
        {
            case 24:
                Mask_255_255_255_0(ipAddress);
                break;
            case 16:
                Mask_255_255_0_0(ipAddress);
                break;
            case 8:
                Mask_255_0_0_0(ipAddress);
                break;
            default:
                Console.WriteLine("Неверный формат маски подсети.");
                break;
        }


    }

    static void Mask_255_255_255_0(IPAddress ipAddress)
    {
        Task[] tasks = new Task[254];

        for (int i = 1; i <= 254; i++)
        {
            string[] ipAddressParts = ipAddress.ToString().Split('.');
            ipAddressParts[3] = i.ToString(); // Обновляем последний октет
            IPAddress currentIpAddress = IPAddress.Parse(string.Join('.', ipAddressParts));

            tasks[i - 1] = Task.Factory.StartNew(() => {
                Ping ping = new Ping();
                PingReply reply = ping.Send(currentIpAddress);

                if (reply.Status == IPStatus.Success)
                {
                    string macAddress = GetMacAddress(currentIpAddress);

                    try
                    {
                        IPHostEntry hostEntry = Dns.GetHostEntry(currentIpAddress);
                        Console.WriteLine($"IP-адрес: {currentIpAddress} доступен, Имя: {hostEntry.HostName}, MAC-адрес: {macAddress}.");
                    }
                    catch (Exception)
                    {
                        Console.WriteLine($"IP-адрес: {currentIpAddress} доступен, Имя: неизвестно, MAC-адрес: {macAddress}.");
                    }
                }
                else
                {
                    Console.WriteLine($"IP-адрес: {currentIpAddress} недоступен.");
                }
            });
        }

        Task.WaitAll(tasks);
    }

    static void Mask_255_255_0_0(IPAddress ipAddress)
    {

        for (int i = 1; i <= 254; i++)
        {
            string[] ipAddressParts = ipAddress.ToString().Split('.');
            ipAddressParts[2] = i.ToString(); // Обновляем предпоследний октет
            IPAddress currentIpAddress = IPAddress.Parse(string.Join('.', ipAddressParts));

            Mask_255_255_255_0(currentIpAddress);

        }

    }

    static void Mask_255_0_0_0(IPAddress ipAddress)
    {
        for (int i = 1; i <= 254; i++)
        {
            string[] ipAddressParts = ipAddress.ToString().Split('.');
            ipAddressParts[1] = i.ToString(); // Обновляем второй октет
            IPAddress currentIpAddress = IPAddress.Parse(string.Join('.', ipAddressParts));

            Mask_255_255_0_0(currentIpAddress);
        }
    }

    static string GetMacAddress(IPAddress ipAddress)
    {
        byte[] macAddr = new byte[6];
        int macAddrLen = macAddr.Length;
        string macAddress = "";
        int ret = SendARP(BitConverter.ToInt32(ipAddress.GetAddressBytes(), 0), 0, macAddr, ref macAddrLen);
        if (ret == 0)
        {
            macAddress = BitConverter.ToString(macAddr, 0, macAddrLen);
        }
        return macAddress;
    }

    [System.Runtime.InteropServices.DllImport("iphlpapi.dll", EntryPoint = "SendARP")]
    internal extern static int SendARP(int destIP, int srcIP, byte[] pMacAddr, ref int phyAddrLen);

    static IPAddress GetNetworkAddress(IPAddress ip, IPAddress mask)
    {
        byte[] ipBytes = ip.GetAddressBytes();
        byte[] maskBytes = mask.GetAddressBytes();

        byte[] resultBytes = new byte[ipBytes.Length];
        for (int i = 0; i < ipBytes.Length; i++)
        {
            resultBytes[i] = (byte)(ipBytes[i] & maskBytes[i]);
        }

       return new IPAddress(resultBytes);
    }

    static int CalculateLoopCount(IPAddress mask)
    {
        byte[] maskBytes = mask.GetAddressBytes();
        int loopCount = 0;
        for (int i = 0; i < maskBytes.Length; i++)
        {
            for (int j = 7; j >= 0; j--)
            {
                if (((maskBytes[i] >> j) & 1) == 0)
                {
                    return loopCount;
                }
                loopCount++;
            }
        }
        return loopCount;
    }

}