在Linux上使用VB.net進行Windows TCP套接字連接

Question

目標是windows和linux之間的vb.net連接。

windows-server（vb.net）：服務器應該在端口4001/tcp上監聽連接，並對數據包執行一些操作。

Dim serverstream As NetworkStream 
Dim serverstreamw As StreamWriter 
Dim serverstreamr As StreamReader 
Dim Server As TcpListener 
Dim serverclient As New TcpClient 
Dim ipendpoint As IPEndPoint = New IPEndPoint(IPAddress.Any, 4001) 
Dim mainthread As Threading.Thread 

Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load 
    mainthread = New Threading.Thread(AddressOf mainserver) 
    mainthread.Start() 
End Sub 

Sub mainserver() 
    Try 
     Server = New TcpListener(ipendpoint) 
     Server.Start() 
     serverclient = Server.AcceptTcpClient 
     serverstream = serverclient.GetStream 
     serverstreamr = New StreamReader(serverstream) 
     serverstreamw = New StreamWriter(serverstream) 
     While True 
      Select Case serverstreamr.ReadLine 
       Case "onl" '........ 
       Case "logoff" '........ 
       Case "iamhere" '........ 
        MessageBox.Show("WORKS!!!") 
      End Select 
     End While 
    Catch 

    End Try 
End Sub 

Linux的客戶端：客戶端應該創建與服務器的連接併發送數據包他。

echo "iamhere" > /dev/tcp/client.ip/4001 

的問題是，它似乎像服務器不開端口4001/TCP。客戶端沒有連接：/

如何解決這個問題？

Answer 1

連接不起作用的原因是因爲您必須在服務器的路由器中使用forward port 4001。目前它由路由器丟棄，因爲該端口未映射到路由器的NAT表中，所以路由器不知道應該向哪個LAN設備發送該數據包。

至於只被顯示一次，如果你那Linux的代碼創建一個新 TCP連接的消息框，然後你必須改變你的代碼收到消息後，丟棄舊的連接：

Try 
    Server = New TcpListener(ipendpoint) 
    Server.Start() 
    While True 'Moved While up here to wait for new connections after every command. 
     serverclient = Server.AcceptTcpClient 
     serverstream = serverclient.GetStream 
     serverstreamr = New StreamReader(serverstream) 
     serverstreamw = New StreamWriter(serverstream) 
     Select Case serverstreamr.ReadLine 
      Case "onl" '........ 
      Case "logoff" '........ 
      Case "iamhere" '........ 
       MessageBox.Show("WORKS!!!") 
     End Select 
     serverclient.Close() 'Close old connection. 
    End While 
Catch 
End Try 

我們這樣做的原因是因爲如果Linux啓動一個新的連接而服務器不啓動，那麼服務器仍然會等待舊的連接上的數據，而這些數據已不再由Linux使用。