無法從微控制器接收UDP數據包

Question

我目前正在通過以太網工作在UDP通信PC <→ARM LM3S6965（Luminary）上。在PC上有一個模擬UDP服務器/客戶端的VB.net應用程序。

當數據包從PC發送到ARM LM3S6965時，數據包接收沒有錯誤，但是當ARM LM3S6965將UDP數據包發送回PC時，數據包在某處丟失（應用程序沒有收到它）。

奇怪的是，WireShark捕獲到PC的這些數據包，看起來它們是有效的。

在Windows中關閉防火牆並沒有幫助。我知道這個主題可能對這個論壇是錯誤的，但任何人都可以解釋爲什麼WireShark捕獲這些數據包，但我的應用程序沒有？ ARM LM3S6965（192.168.0.100），PC（192.168.0.116），發送和接收端口號爲3040，並且我正在從ARM LM3S6965微控制器接收的VB.Net應用程序發送廣播消息。

下面是VB.net代碼：

Public Const mnPort As Int16 = 3040        'Port number to send/recieve data on 
Public Const msBroadcastAddress As String = "255.255.255.255" 'Sends data to all LOCAL listening clients, to send data over WAN you'll need to enter a public (external) IP address of the other client 
Public udpReceivingClient As UdpClient       'Client for handling incoming data 
Public udpSendingClient As UdpClient       'Client for sending data 
Public receivingThread As Thread        'Create a separate thread to listen for incoming data, helps to prevent the form from freezing up 
Public mbiClosing As Boolean = False       'Used to close clients if form is closing 


Public Sub InitializeSender() 
    udpSendingClient = New UdpClient(msBroadcastAddress, mnPort) 
    udpSendingClient.EnableBroadcast = True 
End Sub 

Public Sub InitializeReceiver() 
    udpReceivingClient = New UdpClient(mnPort) 
    'Dim start As ThreadStart = New ThreadStart(AddressOf MT_Receiver) 
    'receivingThread = New Thread(start) 
    'receivingThread.IsBackground = True 
    'receivingThread.Start() 
End Sub 

Public Sub MT_Send_UDP(ByVal lbTxBuffer() As Byte) 

    Try 
     udpSendingClient.Send(lbTxBuffer, lbTxBuffer.Length) 
    Catch ex As Exception 
     MsgBox(ex.ToString) 
    End Try 

    Try 
     udpReceivingClient.BeginReceive(AddressOf MT_RX_Callback, Nothing) 
    Catch ex As Exception 
     MsgBox(ex.ToString) 
    End Try 
End Sub 

Public Sub MT_RX_Callback(ByVal IR As IAsyncResult) 
    Dim endPoint As IPEndPoint = New IPEndPoint(IPAddress.Any, 3040) 
    Dim lbData() As Byte 
    Dim llRet As UInt16 
    If mbiClosing = False Then 
     llRet = udpReceivingClient.Available 
     lbData = udpReceivingClient.EndReceive(IR, endPoint) 

     If llRet > 0 Then 
      MT_Validate_Msg(lbData) 
     End If 

     udpReceivingClient.BeginReceive(AddressOf MT_RX_Callback, Nothing) 
    End If 
End Sub 

Private Sub frmSearchUDP_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing 
    mbiClosing = True 

    udpReceivingClient.Close() 
    udpSendingClient.Close() 
    frmMain.Timer.Enabled = True 
End Sub 

Private Sub frmSearchUDP_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load 
    InitializeSender() 
    InitializeReceiver() 

End Sub 

Answer 1

更多評論，但它太長時間......

No196：42.430628
從192.168.0.168 - > 255.255。 255.255（從您的PC到您的硬件）
UDP ...源端口：63162（63162）
目標端口：番茄溫泉（3040）

這看起來不錯，它顯然工作，因爲您的硬件發送響應。

No197：42.431017
從192.168.0.100 - > 255.255.255.255（從硬件到您的PC）
源端口：番茄彈簧（3040）
目標端口：63162（63162）

爲什麼你的PC應該收到這個數據包？
目的端口是63162，但你聽端口3040