сканировать локальную сеть

public void Connect(
    IPAddress address,
    int port
)

TcpClient tcpClient = new TcpClient ();
IPAddress ipAddress = Dns.GetHostEntry ("www.contoso.com").AddressList[0];
 
tcpClient.Connect (ipAddress, 11003);

using System;
 
using System.Collections.Generic;
 
using System.ComponentModel;
 
using System.Data;
 
using System.Drawing;
 
using System.Text;
 
using System.Net.Sockets;
 
using System.Windows.Forms;
 
namespace PortScanner
 
{
 
  public partial class frmMain : Form
 
  {
 
    protected int StartPort;
 
    protected int EndPort;
 
 
 
    public frmMain()
 
    {
 
      InitializeComponent();
 
    }
 
 
 
    private void btnScan_Click(object sender, EventArgs e)
 
    {
 
      // Store values from the NumericUpDown to variables
 
      StartPort = Convert.ToInt32(numStart.Value);
 
      EndPort = Convert.ToInt32(numEnd.Value);
 
      // Reset the progress bar
 
      prgScanning.Value = 0;
 
      // Set the max value of the progress bar
 
      prgScanning.Maximum = EndPort - StartPort + 1;
 
      // Let the user know the application is busy
 
      Cursor.Current = Cursors.WaitCursor;
 
      // Loop through the ports between start port and end port
 
      for (int CurrPort = StartPort; CurrPort <= EndPort; CurrPort++)
 
      {
 
        TcpClient TcpScan = new TcpClient();
 
        try
 
        {
 
          // Try to connect
 
          TcpScan.Connect(txtIP.Text, CurrPort);
 
          // If there's no exception, we can say the port is open
 
          txtLog.AppendText("Port " + CurrPort + " open\r\n");
 
        }
 
        catch
 
        {
 
          // An exception occured, thus the port is probably closed
 
          txtLog.AppendText("Port " + CurrPort + " closed\r\n");
 
        }
 
        // Increase the progress on the progress bar
 
        prgScanning.PerformStep();
 
      }
 
      // Set the cursor back to normal
 
      Cursor.Current = Cursors.Arrow;
 
    }
 
  }
 
}

public void Connect(
        IPAddress address,
        int port
)