Thursday, March 29, 2012

FTP Task issue

The FTP Task I've created fails. It appears to be making the connection initially behind a firewall, but it suddenly switches from port 21 to port 3397. Anyone experience this issue? Since my firewall is restricting the connection to just port 21, I can't make a permanent connection.

FTP use 2 ports for it work - one for control connection (21) and one for data connection (any other, 3397 in your case, but may be other).|||When a ran a test comparison between the SSIS FTP Task and ftp command line, I only saw this difference when the SSIS FTP Task ran. Is this two-port usage specific to SSIS? I'm able to get out past the firewall using the ftp command without errors. I can't with SSIS.|||FTP use 2 ports by design (you can read RFC about it). Control connection used to transport commands and most simple responses, but file data transferred by data connection, which is open and live while particular transfer goes on.|||I ran a check again and did see windows command-line ftp sending the data transfer on port 20. Thanks.|||

Your problem is this: FTP normally uses ports 20 & 21. But, if you run in passive mode then the remote server will dynamically allocate a port number to you. So, the trick is to run in ACTIVE mode and then you will always run on ports 20 & 21.

If you are running on visual basic and I can let you have some source code to do this.

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