C# code to scan the alive hosts in the network

       

            /// ---------- This code is NOT mine, but i got it from stackoverflow.com 
     /// ---------- which was written by a user named Ken - Abdias Software

 

 

using System.Net.NetworkInformation;
using System.Threading;
using System.Diagnostics;

static class Module1
{


    private static List pingers = new List();
    private static int instances = 0;

    private static object @lock = new object();

    private static int result = 0;
    private static int timeOut = 250;

    private static int ttl = 5;

    public static void Main()
    {
        string baseIP = "192.168.1.";
        int classD = 1;

        Console.WriteLine("Pinging 255 destinations of D-class in {0}*", baseIP);

        CreatePingers(255);

        PingOptions po = new PingOptions(ttl, true);
        System.Text.ASCIIEncoding enc = new System.Text.ASCIIEncoding();
        byte[] data = enc.GetBytes("abababababababababababababababab");

        SpinWait wait = new SpinWait();
        int cnt = 1;

        Stopwatch watch = Stopwatch.StartNew();

        foreach (Ping p in pingers) {
            lock (@lock) {
                instances += 1;
            }

            p.SendAsync(string.Concat(baseIP, cnt.ToString()), timeOut, data, po);
            cnt += 1;
        }

        while (instances > 0) {
            wait.SpinOnce();
        }

        watch.Stop();

        DestroyPingers();

        Console.WriteLine("Finished in {0}. Found {1} active IP-addresses.", watch.Elapsed.ToString(), result);
        Console.ReadKey();

    }


    public static void Ping_completed(object s, PingCompletedEventArgs e)
    {
        lock (@lock) {
            instances -= 1;
        }

        if (e.Reply.Status == IPStatus.Success) {
            Console.WriteLine(string.Concat("Active IP: ", e.Reply.Address.ToString()));
            result += 1;
        } else {
            //Console.WriteLine(String.Concat("Non-active IP: ", e.Reply.Address.ToString()))
        }

    }


    private static void CreatePingers(int cnt)
    {
        for (int i = 1; i <= cnt; i++) {
            Ping p = new Ping();
            p.PingCompleted += Ping_completed;
            pingers.Add(p);
        }
    }

    private static void DestroyPingers()
    {
        foreach (Ping p in pingers) {
            p.PingCompleted -= Ping_completed;
            p.Dispose();
        }

        pingers.Clear();

    }

}