SocketException error

[Simulacra]

Hello,

I am new to VB.Net. I bought this book "Network Programming in .Net" by Fiach Reid, to become familiar with VB and .Net. Anywho, I am testing one of his examples where you create a client that xfers a file to the server. What a great example. So I go ahead and type it in character for character, when I start to run the server in debug it stops at tcpListener.Start()

Here is the method

Public Sub listenerThread()


        Dim myHost As System.Net.IPHostEntry = Dns.GetHostEntry("localhost")
        Dim myIP As System.Net.IPAddress = myHost.AddressList(0)
        Dim tcpListener As New TcpListener(myIP, 80)
        Dim handlerSocket As Socket
        Dim thdstHandler As ThreadStart
        Dim thdHandler As Thread

        tcpListener.Start()

        Do
            handlerSocket = tcpListener.AcceptSocket
            If handlerSocket.Connected Then
                lbConnections.Items.Add(handlerSocket.RemoteEndPoint.ToString() + "Connected.")
                SyncLock (Me)
                    alSockets.Add(handlerSocket)
                End SyncLock
                thdstHandler = New ThreadStart(AddressOf handlerThread)
                thdHandler = New Thread(thdstHandler)
                thdHandler.Start()
            End If
        Loop
    End Sub

The error I get in VB is

SocketException - only one usage of each socket address (protocol/network address/port) is normally permitted.

I am having trouble seeing the problem. Could someone point it out?

Thanks

 

[macleod1021]

You can only have one socket number bindededed at a time

Change your socket number to something unused like 1001. If you're going to do a lot of network programming, I'd recommend researching commonly used socket (or port) numbers.