FTP Question.

[The Brit]

I am trying to pass a file from my laptop to my OpenVMS system. OpenVMS is 8.3-1H1, TCPIP Services version 5.6 ECO 3. (However I get the same result on a system running TCPIP 5.6 ECO 5)

Laptop is running Window XP.

Session log is as follows.

W:\>ftp xxxxxxx.yyyyyy.com
Connected to xxxxxxx.yyyyyy.com.
220 xxxxxxx.yyyyyy.com FTP Server (Version 5.6) Ready.
User (xxxxxxx.yyyyyyy.com:(none)): SYSDAB
331 Username sysdab requires a Password
Password:
230 User logged in.
ftp> dir
200 PORT command successful.
425-Can't build data connection for ,1390
425 device timeout
ftp>
ftp> literal pasv
227 Entering Passive Mode (,243,193)
ftp>
ftp> dir
200 PORT command successful.
425-Can't build data connection for ,1395
425 device timeout
ftp>
ftp> bye
221 Goodbye.

Can anyone suggest why it "Cant build data connection" ?? I am obviously connected (logged in), and I have tried "Passive" mode.

Thanks

Dave.

[labadie_1 · Accepted solution]

Ask the network guys to check port 20

See

http://forums11.itrc.hp.com/service/forums/questionanswer.do?admit=109447626+1270208429056+28353475&threadId=997807 

Admin [above link is no longer valid, please visit https://support.hpe.com/connect/s/  to find the latest info ]

[Volker Halle]

Dave,

just tried these commands to TCPIP T5.7 (Alpha), TCPIP V5.5 (both Alpha and I64). Worked with no problem.

Windows XP SP3 FTP client.

Also try FTP> PASSIVE ON between your OpenVMS systems.

Either it's your FTP client or something in the network.

Volker.

[Hoff]

Presuming that the OpenVMS server has had the ftp daemon configured and launched via TCPIP$CONFIG, this is likely a generic question around the usage and limitations of ftp in modern networks.

If the OpenVMS ftp daemon is running (and barring a degenerate error), then you're almost certainly being blocked by one or likely two firewalls; by port blocks on the ephemeral port range. These blocks are typical and common, because few security administrators wants to have the whole range scanned, and fewer folks have firewalls that can open the proper ports by sniffing the ftp traffic.

http://labs.hoffmanlabs.com/node/530 

Admin [above link is no longer valid]

ftp is good for old stuff and for local stuff, but the protocol inherently stinks around firewalls and modern networks and modern network security.

Here? Consider using sftp. (Via Filezilla, if you're using Microsoft Windows as a client, and your version of Windows lacks sftp tools.) sftp is vastly more easy to punch through a firewall, and it's more secure, and you can set up a passphrase or even a no-password login. Or use a VPN and route all of your traffic to the remote server over the VPN, if you really want to use ftp.

[The Brit]

Thanks for your help guys.

One addition comment, There was no problem FTP'ing between OpenVMS systems, so it looked to be a client problem.

I looked at the suggested forums thread, and tried the suggested telnet command, with the following result.

Welcome to Microsoft Telnet Client

Escape Character is 'CTRL+]'

Microsoft Telnet>
Microsoft Telnet> open xxxxxxx.yyyyyy.com 20
Connecting To xxxxxxx.yyyyyy.com...Could not open connection to the host, on port 20: Connect failed
Microsoft Telnet> q

I tried using sftp, and this worked for me.

So I will try to find out what is happening on port 20, and in the meantime use sftp when I need it.

thanks again.

Dave.

[Richard Whalen]

I don't believe that the Microsoft Windows XP FTP client supports passive mode.
Port 20 is the traditional FTP data port, it won't be open unless there is a data transfer in progress. It would be open on the client side and connect to the port specified in the response to the port command.

[The Brit]

You may be right, however if you look at my original post, it certainly accepts the command

literal pasv

and responds with

227 Entering Passive Mode (,243,193)

(but then again, it is Windowz!)

Dave.

[Jess Goodman]

The "literal PASV" command may APPEAR to work because it puts the server in passive mode. The problem is that your client has to be in passive mode also - passive mode is a differnt way for the client/server to negotiate ports.

But your client has no idea that it should switch to passive mode since it just passed on the "literal" command.