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VB.NET 2005 FTP Program - TCPIP and Sockets using wrong ports and not working through Windows Firewall
See the attached code (670 lines)
This class enables FTP ing via visual basic. I got it free on the internet !! Only problem is, it doesn't work when the target server is running windows firewall.
I caught it in the debugger and the problem is in Private Function CreateDataSocket, on the line "s.Connect(ep)"
The variable "port" in the program is programmatically generated and is a different number each time. Windows firewall is also rejecting other ports as in the below pfirewall.log:
#Version: 1.5
#Software: Microsoft Windows Firewall
#Time Format: Local
#Fields: date time action protocol src-ip dst-ip src-port dst-port size tcpflags tcpsyn tcpack tcpwin icmptype icmpcode info path
2008-06-16 16:48:23 DROP TCP 99.99.108.178 99.99.163.114 3104 1196 48 S 507753288 0 65535 - - - RECEIVE
2008-06-16 16:48:32 DROP TCP 99.99.108.178 99.99.163.114 3104 1196 48 S 507753288 0 65535 - - - RECEIVE
2008-06-16 16:48:26 DROP TCP 99.99.108.178 99.99.163.114 3104 1196 48 S 507753288 0 65535 - - - RECEIVE
2008-06-16 17:59:07 DROP TCP 99.99.108.178 99.99.163.114 3126 1048 48 S 2942101445 0 65535 - - - RECEIVE
2008-06-16 17:59:04 DROP TCP 99.99.108.178 99.99.163.114 3126 1048 48 S 2942101445 0 65535 - - - RECEIVE
2008-06-16 17:59:13 DROP TCP 99.99.108.178 99.99.163.114 3126 1048 48 S 2942101445 0 65535 - - - RECEIVE
So ports 1196 and 1048 were attempted on different calls.
Any ideas how to fix this program so it can work just through port 21 ?
thanks
This class enables FTP ing via visual basic. I got it free on the internet !! Only problem is, it doesn't work when the target server is running windows firewall.
I caught it in the debugger and the problem is in Private Function CreateDataSocket, on the line "s.Connect(ep)"
The variable "port" in the program is programmatically generated and is a different number each time. Windows firewall is also rejecting other ports as in the below pfirewall.log:
#Version: 1.5
#Software: Microsoft Windows Firewall
#Time Format: Local
#Fields: date time action protocol src-ip dst-ip src-port dst-port size tcpflags tcpsyn tcpack tcpwin icmptype icmpcode info path
2008-06-16 16:48:23 DROP TCP 99.99.108.178 99.99.163.114 3104 1196 48 S 507753288 0 65535 - - - RECEIVE
2008-06-16 16:48:32 DROP TCP 99.99.108.178 99.99.163.114 3104 1196 48 S 507753288 0 65535 - - - RECEIVE
2008-06-16 16:48:26 DROP TCP 99.99.108.178 99.99.163.114 3104 1196 48 S 507753288 0 65535 - - - RECEIVE
2008-06-16 17:59:07 DROP TCP 99.99.108.178 99.99.163.114 3126 1048 48 S 2942101445 0 65535 - - - RECEIVE
2008-06-16 17:59:04 DROP TCP 99.99.108.178 99.99.163.114 3126 1048 48 S 2942101445 0 65535 - - - RECEIVE
2008-06-16 17:59:13 DROP TCP 99.99.108.178 99.99.163.114 3126 1048 48 S 2942101445 0 65535 - - - RECEIVE
So ports 1196 and 1048 were attempted on different calls.
Any ideas how to fix this program so it can work just through port 21 ?
thanks
Public Class Ftp
Private m_sRemoteHost, m_sRemotePath, m_sRemoteUser As String
Private m_sRemotePassword, m_sMess As String
Private m_iRemotePort, m_iBytes As Int32
Private m_objClientSocket As System.Net.Sockets.Socket
Private m_iRetValue As Int32
Private m_bLoggedIn As Boolean
Private m_sMes, m_sReply As String
'Set the size of the packet that is used to read and to write data to the FTP server
'to the following specified size.
Public Const BLOCK_SIZE As Integer = 512
Private m_aBuffer(BLOCK_SIZE) As Byte
Private ASCII As System.Text.Encoding = System.Text.Encoding.ASCII
Public flag_bool As Boolean
'General variable declaration
Private m_sMessageString As String
' Parameterized constructor
Public Sub New(ByVal sRemoteHost As String, _
ByVal sRemoteUser As String, _
ByVal sRemotePassword As String, _
ByVal iRemotePort As Int32, _
ByVal sRemotePath As String)
m_sRemoteHost = sRemoteHost
m_sRemotePath = sRemotePath
m_sRemoteUser = sRemoteUser
m_sRemotePassword = sRemotePassword
m_sMessageString = ""
m_iRemotePort = iRemotePort
m_bLoggedIn = False
End Sub
'Set or Get the name of the FTP server that you want to connect.
Public Property RemoteHostFTPServer() As String
'Get the name of the FTP server.
Get
Return m_sRemoteHost
End Get
'Set the name of the FTP server.
Set(ByVal Value As String)
m_sRemoteHost = Value
End Set
End Property
'Set or Get the FTP Port Number of the FTP server that you want to connect.
Public Property RemotePort() As Int32
'Get the FTP Port Number.
Get
Return m_iRemotePort
End Get
'Set the FTP Port Number.
Set(ByVal Value As Int32)
m_iRemotePort = Value
End Set
End Property
'Set or Get the remote path of the FTP server that you want to connect.
Public Property RemotePath() As String
'Get the remote path.
Get
Return m_sRemotePath
End Get
'Set the remote path.
Set(ByVal Value As String)
m_sRemotePath = Value
End Set
End Property
'Set or Get the remote password of the FTP server that you want to connect.
Public Property RemotePassword() As String
Get
Return m_sRemotePassword
End Get
Set(ByVal Value As String)
m_sRemotePassword = Value
End Set
End Property
'Set or Get the remote user of the FTP server that you want to connect.
Public Property RemoteUser() As String
Get
Return m_sRemoteUser
End Get
Set(ByVal Value As String)
m_sRemoteUser = Value
End Set
End Property
'Set the class MessageString.
Public Property MessageString() As String
Get
Return m_sMessageString
End Get
Set(ByVal Value As String)
m_sMessageString = Value
End Set
End Property
'Return a list of files in a string() array from the file system.
Public Function GetFileList(ByVal sMask As String) As String()
Dim cSocket As System.Net.Sockets.Socket
Dim bytes As Int32
Dim seperator As Char = ControlChars.Lf
Dim mess() As String
m_sMes = ""
'Check if you are logged on to the FTP server.
If (Not (m_bLoggedIn)) Then
Login()
End If
cSocket = CreateDataSocket()
'Send an FTP command,
SendCommand("NLST " & sMask)
If (Not (m_iRetValue = 150 Or m_iRetValue = 125)) Then
MessageString = m_sReply
Throw New System.IO.IOException(m_sReply.Substring(4))
End If
m_sMes = ""
Do While (True)
Array.Clear(m_aBuffer, 0, m_aBuffer.Length)
bytes = cSocket.Receive(m_aBuffer, m_aBuffer.Length, 0)
m_sMes += ASCII.GetString(m_aBuffer, 0, bytes)
If (bytes < m_aBuffer.Length) Then
Exit Do
End If
Loop
mess = m_sMes.Split(seperator)
cSocket.Close()
ReadReply()
If (m_iRetValue <> 226) Then
MessageString = m_sReply
Throw New System.IO.IOException(m_sReply.Substring(4))
End If
Return mess
End Function
' Get the size of the file on the FTP server.
Public Function GetFileSize(ByVal sFileName As String) As Long
Dim size As Long
If (Not (m_bLoggedIn)) Then
Login()
End If
'Send an FTP command.
SendCommand("SIZE " & sFileName)
size = 0
If (m_iRetValue = 213) Then
size = Int64.Parse(m_sReply.Substring(4))
Else
MessageString = m_sReply
Throw New System.IO.IOException(m_sReply.Substring(4))
End If
Return size
End Function
'Log on to the FTP server.
Public Function Login() As Boolean
m_objClientSocket = New System.Net.Sockets.Socket(System.Net.Sockets.AddressFamily.InterNetwork, System.Net.Sockets.SocketType.Stream, System.Net.Sockets.ProtocolType.Tcp)
Dim ep As New System.Net.IPEndPoint(Net.IPAddress.Parse(m_sRemoteHost), m_iRemotePort)
Try
m_objClientSocket.Connect(ep)
Catch ex As Exception
MessageString = m_sReply
Throw New System.IO.IOException("Cannot connect to remote server")
End Try
ReadReply()
If (m_iRetValue <> 220) Then
CloseConnection()
MessageString = m_sReply
Throw New System.IO.IOException(m_sReply.Substring(4))
End If
'Send an FTP command to send a user logon ID to the server.
SendCommand("USER " & m_sRemoteUser)
If (Not (m_iRetValue = 331 Or m_iRetValue = 230)) Then
Cleanup()
MessageString = m_sReply
Throw New System.IO.IOException(m_sReply.Substring(4))
End If
If (m_iRetValue <> 230) Then
'Send an FTP command to send a user logon password to the server.
SendCommand("PASS " & m_sRemotePassword)
If (Not (m_iRetValue = 230 Or m_iRetValue = 202)) Then
Cleanup()
MessageString = m_sReply
Throw New System.IO.IOException(m_sReply.Substring(4))
End If
End If
m_bLoggedIn = True
'Call the ChangeDirectory user-defined function to change the folder to the
'remote FTP folder that is mapped.
ChangeDirectory(m_sRemotePath)
'Return the final result.
Return m_bLoggedIn
End Function
'If the value of mode is true, set the binary mode for downloads. Otherwise, set ASCII mode.
Public Sub SetBinaryMode(ByVal bMode As Boolean)
If (bMode) Then
'Send the FTP command to set the binary mode.
'(TYPE is an FTP command that is used to specify representation type.)
SendCommand("TYPE I")
Else
'Send the FTP command to set ASCII mode.
'(TYPE is a FTP command that is used to specify representation type.)
SendCommand("TYPE A")
End If
If (m_iRetValue <> 200) Then
MessageString = m_sReply
Throw New System.IO.IOException(m_sReply.Substring(4))
End If
End Sub
Public Sub SetSiteFileType(ByVal FileType As String)
Dim cmdString As New System.Text.StringBuilder
cmdString.Append("site filetype=").Append(FileType)
SendCommand(cmdString.ToString)
If (m_iRetValue <> 200) Then
MessageString = m_sReply
Throw New System.IO.IOException(m_sReply.Substring(4))
End If
End Sub
' Download a file to the local folder of the assembly, and keep the same file name.
Public Sub DownloadFile(ByVal sFileName As String)
DownloadFile(sFileName, "", False)
End Sub
' Download a remote file to the local folder of the assembly, and keep the same file name.
Public Sub DownloadFile(ByVal sFileName As String, _
ByVal bResume As Boolean)
DownloadFile(sFileName, "", bResume)
End Sub
'Download a remote file to a local file name. You must include a path.
'The local file name will be created or will be overwritten, but the path must exist.
Public Sub DownloadFile(ByVal sFileName As String, _
ByVal sLocalFileName As String)
DownloadFile(sFileName, sLocalFileName, False)
End Sub
' Download a remote file to a local file name and include a path. Then, set the
' resume flag. The local file name will be created or will be overwritten, but the path must exist.
Public Sub DownloadFile(ByVal sFileName As String, _
ByVal sLocalFileName As String, _
ByVal bResume As Boolean)
Dim st As System.IO.Stream
Dim output As System.IO.FileStream
Dim cSocket As System.Net.Sockets.Socket
Dim offset, npos As Long
If (Not (m_bLoggedIn)) Then
Login()
End If
'SetBinaryMode(True)
If (sLocalFileName.Equals("")) Then
sLocalFileName = sFileName
End If
If (Not (System.IO.File.Exists(sLocalFileName))) Then
st = System.IO.File.Create(sLocalFileName)
st.Close()
End If
output = New System.IO.FileStream(sLocalFileName, System.IO.FileMode.Open)
cSocket = CreateDataSocket()
offset = 0
If (bResume) Then
offset = output.Length
If (offset > 0) Then
'Send an FTP command to restart.
SendCommand("REST " & offset)
If (m_iRetValue <> 350) Then
offset = 0
End If
End If
If (offset > 0) Then
npos = output.Seek(offset, System.IO.SeekOrigin.Begin)
End If
End If
'Send an FTP command to retrieve a file.
SendCommand("RETR " & sFileName)
If (Not (m_iRetValue = 150 Or m_iRetValue = 125)) Then
output.Close()
MessageString = m_sReply
Throw New System.IO.IOException(m_sReply.Substring(4))
End If
Do While (True)
Array.Clear(m_aBuffer, 0, m_aBuffer.Length)
m_iBytes = cSocket.Receive(m_aBuffer, m_aBuffer.Length, 0)
output.Write(m_aBuffer, 0, m_iBytes)
If (m_iBytes <= 0) Then
Exit Do
End If
Loop
output.Close()
If (cSocket.Connected) Then
cSocket.Close()
End If
ReadReply()
If (Not (m_iRetValue = 226 Or m_iRetValue = 250)) Then
MessageString = m_sReply
Throw New System.IO.IOException(m_sReply.Substring(4))
End If
End Sub
' Delete a file from the remote FTP server.
Public Function DeleteFile(ByVal sFileName As String) As Boolean
Dim bResult As Boolean
bResult = True
If (Not (m_bLoggedIn)) Then
Login()
End If
'Send an FTP command to delete a file.
SendCommand("DELE " & sFileName)
If (m_iRetValue <> 250) Then
bResult = False
MessageString = m_sReply
End If
' Return the final result.
Return bResult
End Function
' Rename a file on the remote FTP server.
Public Function RenameFile(ByVal sOldFileName As String, _
ByVal sNewFileName As String) As Boolean
Dim bResult As Boolean
bResult = True
If (Not (m_bLoggedIn)) Then
Login()
End If
'Send an FTP command to rename a file.
SendCommand("RNFR " & sOldFileName)
If (m_iRetValue <> 350) Then
MessageString = m_sReply
Throw New System.IO.IOException(m_sReply.Substring(4))
End If
'Send an FTP command to rename a file to a file name.
'It will overwrite if newFileName exists.
SendCommand("RNTO " & sNewFileName)
If (m_iRetValue <> 250) Then
MessageString = m_sReply
Throw New System.IO.IOException(m_sReply.Substring(4))
End If
' Return the final result.
Return bResult
End Function
'This is a function that is used to create a folder on the remote FTP server.
Public Function CreateDirectory(ByVal sDirName As String) As Boolean
Dim bResult As Boolean
bResult = True
If (Not (m_bLoggedIn)) Then
Login()
End If
'Send an FTP command to make a folder on the FTP server.
SendCommand("MKD " & sDirName)
If (m_iRetValue <> 257) Then
bResult = False
MessageString = m_sReply
End If
' Return the final result.
Return bResult
End Function
' This is a function that is used to delete a folder on the remote FTP server.
Public Function RemoveDirectory(ByVal sDirName As String) As Boolean
Dim bResult As Boolean
bResult = True
'Check if you are logged on to the FTP server.
If (Not (m_bLoggedIn)) Then
Login()
End If
'Send an FTP command to remove a folder on the FTP server.
SendCommand("RMD " & sDirName)
If (m_iRetValue <> 250) Then
bResult = False
MessageString = m_sReply
End If
' Return the final result.
Return bResult
End Function
'This is a function that is used to change the current working folder on the remote FTP server.
Public Function ChangeDirectory(ByVal sDirName As String) As Boolean
Dim bResult As Boolean
bResult = True
'Check if you are in the root directory.
If (sDirName.Equals(".")) Then
Exit Function
End If
'Check if you are logged on to the FTP server.
If (Not (m_bLoggedIn)) Then
Login()
End If
'Send an FTP command to change the folder on the FTP server.
SendCommand("CWD " & sDirName)
If (m_iRetValue <> 250) Then
bResult = False
MessageString = m_sReply
End If
Me.m_sRemotePath = sDirName
' Return the final result.
Return bResult
End Function
' Close the FTP connection of the remote server.
Public Sub CloseConnection()
If (Not (m_objClientSocket Is Nothing)) Then
'Send an FTP command to end an FTP server system.
SendCommand("QUIT")
End If
Cleanup()
End Sub
' Read the reply from the FTP server.
Private Sub ReadReply()
m_sMes = ""
m_sReply = ReadLine()
m_iRetValue = Int32.Parse(m_sReply.Substring(0, 3))
End Sub
' Clean up some variables.
Private Sub Cleanup()
If Not (m_objClientSocket Is Nothing) Then
m_objClientSocket.Close()
m_objClientSocket = Nothing
End If
m_bLoggedIn = False
End Sub
' Read a line from the FTP server.
Private Function ReadLine(Optional ByVal bClearMes As Boolean = False) As String
Dim seperator As Char = ControlChars.Lf
Dim mess() As String
If (bClearMes) Then
m_sMes = ""
End If
Do While (True)
Array.Clear(m_aBuffer, 0, BLOCK_SIZE)
m_iBytes = m_objClientSocket.Receive(m_aBuffer, m_aBuffer.Length, 0)
m_sMes += ASCII.GetString(m_aBuffer, 0, m_iBytes)
If (m_iBytes < m_aBuffer.Length) Then
Exit Do
End If
Loop
mess = m_sMes.Split(seperator)
If (m_sMes.Length > 2) Then
m_sMes = mess(mess.Length - 2)
Else
m_sMes = mess(0)
End If
'TODO fix problem reading zero length field
If (Not (m_sMes.Substring(3, 1).Equals(" "))) Then
Return ReadLine(True)
End If
Return m_sMes
End Function
' This is a function that is used to send a command to the FTP server that you are connected to.
Private Sub SendCommand(ByVal sCommand As String)
sCommand = sCommand & ControlChars.CrLf
Dim cmdbytes As Byte() = ASCII.GetBytes(sCommand)
m_objClientSocket.Send(cmdbytes, cmdbytes.Length, 0)
ReadReply()
End Sub
' Create a data socket.
Private Function CreateDataSocket() As System.Net.Sockets.Socket
Dim index1, index2, len As Int32
Dim partCount, i, port As Int32
Dim ipData, buf, ipAddress As String
Dim parts(6) As Int32
Dim ch As Char
Dim s As System.Net.Sockets.Socket
Dim ep As System.Net.IPEndPoint
'Send an FTP command to use a passive data connection.
SendCommand("PASV")
If (m_iRetValue <> 227) Then
MessageString = m_sReply
Throw New System.IO.IOException(m_sReply.Substring(4))
End If
index1 = m_sReply.IndexOf("(")
index2 = m_sReply.IndexOf(")")
ipData = m_sReply.Substring(index1 + 1, index2 - index1 - 1)
len = ipData.Length
partCount = 0
buf = ""
For i = 0 To len - 1
If partCount > 6 Then
Exit For
End If
ch = Char.Parse(ipData.Substring(i, 1))
If (Char.IsDigit(ch)) Then
buf += ch
ElseIf (ch <> ",") Then
MessageString = m_sReply
Throw New System.IO.IOException("Malformed PASV reply: " & m_sReply)
End If
If ((ch = ",") Or (i + 1 = len)) Then
Try
parts(partCount) = Int32.Parse(buf)
partCount += 1
buf = ""
Catch ex As Exception
MessageString = m_sReply
Throw New System.IO.IOException("Malformed PASV reply: " & m_sReply)
End Try
End If
Next
ipAddress = parts(0) & "." & parts(1) & "." & parts(2) & "." & parts(3)
' Make this call in Visual Basic .NET 2002. You want to
' bitshift the number by 8 bits. Therefore, in Visual Basic .NET 2002, you must
' multiply the number by 2 to the power of 8.
'port = parts(4) * (2 ^ 8)
' Make this call and then comment out the previous line for Visual Basic .NET 2003.
port = parts(4) << 8
' Determine the data port number.
port = port + parts(5)
s = New System.Net.Sockets.Socket(System.Net.Sockets.AddressFamily.InterNetwork, System.Net.Sockets.SocketType.Stream, System.Net.Sockets.ProtocolType.Tcp)
'ep = New System.Net.IPEndPoint(Dns.Resolve(ipAddress).AddressList(0), port)
ep = New System.Net.IPEndPoint(Net.IPAddress.Parse(ipAddress), port)
Try
s.Connect(ep) /// ********* THIS IS THE PROBLEM LINE - EP.port is not 21 - so this hits windows firewall and times out ********** ////////
Catch ex As Exception
MessageString = m_sReply
Throw New System.IO.IOException("Cannot connect to remote server")
'If you cannot connect to the FTP
'server that is specified, make the boolean variable false.
flag_bool = False
End Try
'If you can connect to the FTP server that is specified, make the boolean variable true.
flag_bool = True
Return s
End Function
Public Sub UploadFile(ByVal sFileName As String, ByVal sUploadName As String, _
ByVal bResume As Boolean)
Dim cSocket As System.Net.Sockets.Socket
Dim offset As Long
Dim input As System.IO.FileStream
Dim bFileNotFound As Boolean
If (Not (m_bLoggedIn)) Then
Login()
End If
cSocket = CreateDataSocket()
offset = 0
If (bResume) Then
Try
'SetBinaryMode(True)
offset = GetFileSize(sFileName)
Catch ex As Exception
offset = 0
End Try
End If
If (offset > 0) Then
SendCommand("REST " & offset)
If (m_iRetValue <> 350) Then
'The remote server may not support resuming.
offset = 0
End If
End If
'Send an FTP command to store a file.
SendCommand("STOR " & sUploadName)
If (Not (m_iRetValue = 125 Or m_iRetValue = 150)) Then
MessageString = m_sReply
Throw New System.IO.IOException(m_sReply.Substring(4))
End If
'Check to see if the file exists before the upload.
bFileNotFound = False
If (System.IO.File.Exists(sFileName)) Then
' Open the input stream to read the source file.
input = New System.IO.FileStream(sFileName, System.IO.FileMode.Open)
If (offset <> 0) Then
input.Seek(offset, System.IO.SeekOrigin.Begin)
End If
'Upload the file.
m_iBytes = input.Read(m_aBuffer, 0, m_aBuffer.Length)
Do While (m_iBytes > 0)
cSocket.Send(m_aBuffer, m_iBytes, 0)
m_iBytes = input.Read(m_aBuffer, 0, m_aBuffer.Length)
Loop
input.Close()
Else
bFileNotFound = True
End If
If (cSocket.Connected) Then
cSocket.Close()
End If
'Check the return value if the file was not found.
If (bFileNotFound) Then
MessageString = m_sReply
Throw New System.IO.IOException("The file: " & sFileName & " was not found." & _
" Cannot upload the file to the FTP site.")
End If
ReadReply()
If (Not (m_iRetValue = 226 Or m_iRetValue = 250)) Then
MessageString = m_sReply
Throw New System.IO.IOException(m_sReply.Substring(4))
End If
End Sub
End Class
ASKER
Thanks Sunny - I appreciate you coming across to vb to help..
Yes I tried that yesterday. It does get further.. The line that actually uploads the ftp file fails with error 425..
'Send an FTP command to store a file.
SendCommand("STOR " & sUploadName)
If (Not (m_iRetValue = 125 Or m_iRetValue = 150)) Then
MessageString = m_sReply
Throw New System.IO.IOException(m_sR eply.Subst ring(4))
End If
in function "UploadFile" then throws an exception because m_iRetVal returned 425 - cant open connection
Yes I tried that yesterday. It does get further.. The line that actually uploads the ftp file fails with error 425..
'Send an FTP command to store a file.
SendCommand("STOR " & sUploadName)
If (Not (m_iRetValue = 125 Or m_iRetValue = 150)) Then
MessageString = m_sReply
Throw New System.IO.IOException(m_sR
End If
in function "UploadFile" then throws an exception because m_iRetVal returned 425 - cant open connection
ASKER
The problem seems to be that the programmer decided to use a "passive data connection", where the server decides the port for you randomly..
So now I am reseaching what an alternative might be ...
So now I am reseaching what an alternative might be ...
That means you have a control connection in place but cant open a data connection
http://support.microsoft.com/kb/129395
If an FTP error 425 occurs, this indicates that the server was unable to open the connection back to the client. The most likely cause for this is an FTP client application that is attempting to re-use a socket that is still in the TCP TIME-WAIT state due to an earlier connection that hasn't been timed out yet.
Issue appears to be something else
http://support.microsoft.com/kb/129395
If an FTP error 425 occurs, this indicates that the server was unable to open the connection back to the client. The most likely cause for this is an FTP client application that is attempting to re-use a socket that is still in the TCP TIME-WAIT state due to an earlier connection that hasn't been timed out yet.
Issue appears to be something else
ASKER
I think the problem is that the data connection is opened on a port which is blocked by windows firewall
This thread below seems helpful in understanding why FTP needs 2 ports to work. But then I'm left wondering why FTP.EXE works fine through windows firewall port 21 but my program doesn't
http://www.tcpipguide.com/free/t_FTPDataConnectionManagementNormalActiveandPassiveD-3.htm
The thread states that port 21 is used as the control connection but having a data connection on the same port is "a bad idea" !!
I think creating a "NORMAL" data connection instead of a PASV connection passive connection sound like it might work ?? Or perhaps I should go back to BAT files !
This thread below seems helpful in understanding why FTP needs 2 ports to work. But then I'm left wondering why FTP.EXE works fine through windows firewall port 21 but my program doesn't
http://www.tcpipguide.com/free/t_FTPDataConnectionManagementNormalActiveandPassiveD-3.htm
The thread states that port 21 is used as the control connection but having a data connection on the same port is "a bad idea" !!
I think creating a "NORMAL" data connection instead of a PASV connection passive connection sound like it might work ?? Or perhaps I should go back to BAT files !
Is there a firewall on your client machine that is causing issues? Windows FTP.exe might be on white list of this firewall.
The firewall to the remote server should not block outgoing connections.
If that does not work, to be sure that this is not a case of stale connections, can you reboot once and try.
The firewall to the remote server should not block outgoing connections.
If that does not work, to be sure that this is not a case of stale connections, can you reboot once and try.
ASKER
No, I'm in a network of about 20 pcs in the uk, and the ftp server is a webserver on ThePlanet...
My network is firewalled with a cisco firewall. I don't think its stale connections as they're not showing up in the server iis and ftp.exe works every time.
The windows firewall log is showing these "ephemeral ports" as rejected, so thats obviously stopping it working.
This thread gives a better clue... but no code showing what SENDCOMMAND commands are needed to use the ftp standard method instead of passive method
My network is firewalled with a cisco firewall. I don't think its stale connections as they're not showing up in the server iis and ftp.exe works every time.
The windows firewall log is showing these "ephemeral ports" as rejected, so thats obviously stopping it working.
This thread gives a better clue... but no code showing what SENDCOMMAND commands are needed to use the ftp standard method instead of passive method
If you are expecting to do active FTP, you'll need your client to accept a connection from the server. Generally that's harder to set up in your firewall than passive FTP, which simply requires that your client needs to be able to connect to an unprivileged port > 1023 on the server as well as the privileged command port 21.
Here's a nice explanation: http://slacksite.com/other/ftp.html
Here's a nice explanation: http://slacksite.com/other/ftp.html
Can't you get your firewall set up to allow connections to > 1023 on the FTP servers? Allowing active FTP connections back to your 20 client PCs will be tricky if you are going through NAT.
ASKER
I don't think windows firewall lets you setup a port range, I'd have to create every port from 1023 to 5000 odd manually ??
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> Not ideal to have to open ports but thankfully those ports can be restricted to certain IPs only so not a security risk unless there are more bugs in windows firewall :)
Those are outbound ports remember. I'm not up to speed with Windows firewall, but I expect that will only set up firewall holes for established connections (i.e. it will not be allow listening for new connections on that port).
Good job you don't have to mess around with the Cisco firewall for this, eh? Network administrators come from the same school of thought as traffic wardens and dictators.
Those are outbound ports remember. I'm not up to speed with Windows firewall, but I expect that will only set up firewall holes for established connections (i.e. it will not be allow listening for new connections on that port).
Good job you don't have to mess around with the Cisco firewall for this, eh? Network administrators come from the same school of thought as traffic wardens and dictators.
[By the way, no issues here with the point allocation and flagging http:#21801614 as the correct solution in the PAQ.]
ASKER
FYI no they are inbound ports because we are putting settings on the server windows firewall
vb.net > my dev pc in my network | cisco firewall | internet | TP firewall | win firewall on server > server at TP
Windows firewall holes apply to existing connections and new connections but you can lock down to only open that port to certain ip addresses which works for me..
thanks for your help
vb.net > my dev pc in my network | cisco firewall | internet | TP firewall | win firewall on server > server at TP
Windows firewall holes apply to existing connections and new connections but you can lock down to only open that port to certain ip addresses which works for me..
thanks for your help
s.Connect(ep) /// ********* THIS IS THE PROBLEM LINE - EP.port is not 21 - so this hits windows firewall and times out ********** ////////
I am not very familiar with VB but shouldn't this work
Try
ep.port = 21
s.Connect(ep) /// ********* THIS IS THE PROBLEM LINE - EP.port is not 21 - so this hits windows firewall and times out ********** ////////