与Windows 8到z / OS的FTP失败，并显示“无法打开数据连接”

Question

Has anyone successfully used FTP between az/OS systems (running z/OS V1.13 or V2.2) and a windows 8.1 Enterprise machines? We used to do this without any problems under XP but then our XP desktops were replaces with laptops running Windows 8, and FTP no longer works.

When stating an FTP sessions from the Windows shell, I can log onto the mainframe, but can no longer access any files.

We raised a ticket with our desktop support team, thinking that perhaps one of the ports used by FTP, which was previously open under XP, was being blocked by the Windows 8 firewall. they are unable to solve the problem.

As an interim solution, we can FTP from z/OS to/from a Solaris FTP server in our organisation and from that server we can FTP to/from our Windows 8 desktops.

I can also use WinSCP to FTP to/from files stored in the USS side of our z/OS system, so individually everything seems to be working. WinSCP can also talk to the Solaris FTP server (using SFTP, I think).

Is there any fundamental issue with FTP between these 2 platforms? (Windows 8 and z/OS).

Edit - here is the log when trying to FTP from a Windows DOS prompt. there was a long wait between the 200 Port request OK. and the 425 Unable to open data connection.

H:\>ftp 10.179.1.1
Connected to 10.179.1.1.
220-FTPD1 IBM FTP CS V1R13 at JXSF.BC.JSPLC.NET, 11:22:33 on 2016-11-24.
220 Connection will close if idle for more than 5 minutes.
User (10.179.1.1:(none)): jbsp03
331 Send password please.
Password:
230 JBSP03 is logged on.  Working directory is "JSDBSP.".
ftp> ls
200 Port request OK.
425 Unable to open data connection.
ftp>

I can't seems to get WinSCP to attempt to connect to the z/OS environment - FTP requests seems to be directed to the USS environment. At a previous site I could use WinSCP to connect to both, depending upon (I think) whether I used FTP or SFTP.

Answer 1

Windows built-in command-line FTP client, the ftp.exe supports active FTP mode only.

In the active mode, the server has to connect back to the client machine to transfer files and to retrieve directory listing.

With the default configuration, the incoming connection is blocked by Windows firewall. Hence the:

425 Unable to open data connection.

I believe was the same on Windows XP (at least on SP2), but you might had the firewall disabled on the XP or you might had explicit rules to enable the incoming connection.

You can do the same on Windows 8.

See my article about network configuration for FTP active mode for details.

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Or use another command-line/scriptable FTP client, that supports a passive mode (most do). In the passive mode, the client connects to the server, what is problem-free usually.

As you are using my WinSCP FTP client already, you can use it instead of the ftp.exe . WinSCP has a scripting interface and there's a guide for converting Windows FTP scripts to WinSCP scripts . WinSCP defaults to the passive mode.