從Azure網站上載文件到FTP時出現“ 425無法打開數據連接”

Question

我想將Azure Web App創建的文件傳輸到Azure網絡外部的FTP服務器。 我得到的只是FTP上的0字節文件和Web App上的“ 425無法打開數據連接”錯誤。

Azure Web App或FTP服務器上是否缺少我的設置？ 我的本地IIS Express上的同一Web應用程序運行正常。 該Web應用程序使用ASP .NET MVC 5。

編輯1：

這是我用來發送文件的代碼：

FtpWebRequest ftpRequest = (FtpWebRequest)WebRequest.Create(ftp + fileName);
ftpRequest.Method = WebRequestMethods.Ftp.UploadFile;
ftpRequest.Credentials = new NetworkCredential(uid, pwd);
ftpRequest.ContentLength = fileBytes.Length;

Stream requestStream = ftpRequest.GetRequestStream();
requestStream.Write(fileBytes, 0, fileBytes.Length);
requestStream.Close();

FtpWebResponse response = (FtpWebResponse)ftpRequest.GetResponse();
var status = response.StatusCode;
response.Close();

根據MSDN ，被動模式是默認模式。

編輯2：

啟用服務器日志記錄，這是輸出：

System.Net Information: 0 : [60572] FtpControlStream#51898079 - Created connection from <origin_ip> to <destination_ip>.
System.Net Information: 0 : [60572] Associating FtpWebRequest#23597360 with FtpControlStream#51898079
System.Net Information: 0 : [60572] FtpControlStream#51898079 - Received response [220 Microsoft FTP Service]
System.Net Information: 0 : [60572] FtpControlStream#51898079 - Sending command [USER <user>]
System.Net Information: 0 : [60572] FtpControlStream#51898079 - Received response [331 Password required for <user>.]
System.Net Information: 0 : [60572] FtpControlStream#51898079 - Sending command [PASS *]
System.Net Information: 0 : [60572] FtpControlStream#51898079 - Received response [230 User <user> logged in.]
System.Net Information: 0 : [60572] FtpControlStream#51898079 - Sending command [OPTS utf8 on]
System.Net Information: 0 : [60572] FtpControlStream#51898079 - Received response [501 option not supported]
System.Net Information: 0 : [60572] FtpControlStream#51898079 - Sending command [PWD]
System.Net Information: 0 : [60572] FtpControlStream#51898079 - Received response [257 "/" is current directory.]
System.Net Information: 0 : [60572] FtpControlStream#51898079 - Sending command [TYPE I]
System.Net Information: 0 : [60572] FtpControlStream#51898079 - Received response [200 Type set to I.]
System.Net Information: 0 : [60572] FtpControlStream#51898079 - Sending command [PASV]
System.Net Information: 0 : [60572] FtpControlStream#51898079 - Received response [227 Entering Passive Mode (12,106,237,74,4,255).]
System.Net Information: 0 : [60572] FtpControlStream#51898079 - Sending command [STOR <file>]
System.Net Information: 0 : [60572] FtpControlStream#51898079 - Received response [425 Can't open data connection.]
System.Net Information: 0 : [60572] FtpWebRequest#23597360::(Releasing FTP connection#51898079.)
System.Net Error: 0 : [60572] Exception in FtpWebRequest#23597360::GetRequestStream - The remote server returned an error: (425) Can't open data connection..
   at System.Net.FtpWebRequest.SyncRequestCallback(Object obj)
   at System.Net.FtpWebRequest.RequestCallback(Object obj)
   at System.Net.CommandStream.Dispose(Boolean disposing)
   at System.IO.Stream.Close()
   at System.IO.Stream.Dispose()
   at System.Net.ConnectionPool.Destroy(PooledStream pooledStream)
   at System.Net.ConnectionPool.PutConnection(PooledStream pooledStream, Object owningObject, Int32 creationTimeout, Boolean canReuse)
   at System.Net.FtpWebRequest.FinishRequestStage(RequestStage stage)
   at System.Net.FtpWebRequest.GetRequestStream()

編輯3：

另一嘗試：

System.Net Information: 0 : [58636] FtpWebRequest#9144495::.ctor(<ftp_address_and_file>)
System.Net Information: 0 : [58636] FtpWebRequest#9144495::GetRequestStream(Method=STOR.)
System.Net Information: 0 : [58636] FtpControlStream#57089836 - Created connection from <origin_ip> to <destination_ip>.
System.Net Information: 0 : [58636] Associating FtpWebRequest#9144495 with FtpControlStream#57089836
System.Net Information: 0 : [58636] FtpControlStream#57089836 - Received response [220 Microsoft FTP Service]
System.Net Information: 0 : [58636] FtpControlStream#57089836 - Sending command [USER <user>]
System.Net Information: 0 : [58636] FtpControlStream#57089836 - Received response [331 Password required for <user>.]
System.Net Information: 0 : [58636] FtpControlStream#57089836 - Sending command [PASS *]
System.Net Information: 0 : [58636] FtpControlStream#57089836 - Received response [230 User <user> logged in.]
System.Net Information: 0 : [58636] FtpControlStream#57089836 - Sending command [OPTS utf8 on]
System.Net Information: 0 : [58636] FtpControlStream#57089836 - Received response [501 option not supported]
System.Net Information: 0 : [58636] FtpControlStream#57089836 - Sending command [PWD]
System.Net Information: 0 : [58636] FtpControlStream#57089836 - Received response [257 "/" is current directory.]
System.Net Information: 0 : [58636] FtpControlStream#57089836 - Sending command [TYPE I]
System.Net Information: 0 : [58636] FtpControlStream#57089836 - Received response [200 Type set to I.]
System.Net Information: 0 : [58636] FtpControlStream#57089836 - Sending command [PASV]
System.Net Information: 0 : [58636] FtpControlStream#57089836 - Received response [227 Entering Passive Mode (12,106,237,74,5,4).]
System.Net Information: 0 : [58636] FtpControlStream#57089836 - Sending command [STOR <file>]
System.Net Information: 0 : [58636] FtpWebRequest#9144495::(Releasing FTP connection#57089836.)
System.Net Error: 0 : [58636] Exception in FtpWebRequest#9144495::GetRequestStream - The operation has timed out..
   at System.Net.FtpWebRequest.SyncRequestCallback(Object obj)
   at System.Net.FtpWebRequest.RequestCallback(Object obj)
   at System.Net.CommandStream.Dispose(Boolean disposing)
   at System.IO.Stream.Close()
   at System.IO.Stream.Dispose()
   at System.Net.ConnectionPool.Destroy(PooledStream pooledStream)
   at System.Net.ConnectionPool.PutConnection(PooledStream pooledStream, Object owningObject, Int32 creationTimeout, Boolean canReuse)
   at System.Net.FtpWebRequest.FinishRequestStage(RequestStage stage)
   at System.Net.FtpWebRequest.GetRequestStream()

Answer 1

當無法打開數據連接進行傳輸時， “無法打開數據連接”是FileZilla FTP服務器發出的消息。

當客戶端在NAT或防火牆后使用活動FTP模式並將其內部IP地址報告給服務器時，通常會發生什么情況，而又不知道服務器無法回到該IP地址。

最簡單（通常正確）的解決方案是使用FTP被動模式，而不是主動模式。

請參閱我關於FTP連接模式的文章，以了解主動和被動模式的含義，以及當今為什么每個人都使用被動模式。

Answer 2

嘗試在客戶端中切換到FTP被動模式。