範例一：

Localhost = 127.0.0.1

如何得知自己的IP呢??(注意：IP可以很多組)

表單加入Textbox1, Button1

Imports System.Net
Imports System.Net.Sockets

Public Class Form1

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

End Sub

Private Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim myHostName As String = System.Net.Dns.GetHostName()
Dim i As Integer
Dim ipE As System.Net.IPHostEntry = System.Net.Dns.GetHostByName(myHostName)
Dim IpA() As System.Net.IPAddress = ipE.AddressList
For i = 0 To IpA.GetUpperBound(0)
TextBox1.Text = ("IP Address " & i.ToString & " " & IpA(i).ToString)
Next
End Sub
End Class

範例二：

nslookup www.yahoo.com

有些DNS至少有一個以上的IP

(承範例一)表單再加入Listbox1, Button2

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Dim ipHost As IPHostEntry

'ipHost = Dns.GetHostByName(strMachineName)
'你可以得到網路上任何DNS的IP訊息。
'語法如下：

ipHost = Dns.GetHostByName("www.yahoo.com")

TextBox1.Text = ("Host Aliases: " + ipHost.Aliases.Length.ToString())

'以陣列的形式傳回相關主機的IP訊息
Dim ipAddr() As IPAddress = ipHost.AddressList
Dim count As Integer

'Enumerate the IP Addresses

For count = 0 To ipAddr.GetUpperBound(0)
ListBox1.Items.Add("IP Address (" & count + 1 & "): " & ipAddr(count).ToString)

Next

End Sub

範例三：

tcp 時間同步連線

SERVER端開啟命令提示字元，輸入DateTimeServer

用戶端在命令提示字元下以telnet [IP] 13 (請注意防火牆須開啟PORT 13)

範例四：

使用WebRequest下載網頁原始碼

本範例是利用程式下載中央氣象局的網頁內容，可以解析並且取得氣象資訊。

範例五：

本機動態連線狀況

本範例是程式動態取得本機連線狀態，Port(就是後門)被打開的顯示狀況。