FTP Fiddling

[major_clanger]

Anyone have any idea why I might be having problems ftp'ing files from my iBook to my filespace on Cix?

I wanted to upload some pics to link to them from LJ and as this was the first time I'd done this from my Mac I found a simple ftp client (Transmit) that would, it seemed, do the job for me.

Well, I could log in to Cix and view my existing files, but every attempt to upload ended with the transfer stalling and a zero-size file being created at the far end.

I then tried the UNIX command-line ftp. Exactly the same result.

I've checked my router firewall settings, and it is configured to allow all outgoing services. As for the OSX firewall, as I understand it the 'ftp' setting is for incoming services, not outgoing.

So what am I missing?

MC

Comments

[ffutures.livejournal.com]

Obvious thought - is there enough room?

2nd obvious thought - have you tried doing it from the browser using the file transfer links that cix online provides?

[major-clanger.livejournal.com]

I am probably being rather thick here, but that seems to lead to the 'Document Library' that CIX Online now provides, which seems to be distinct from the publically-accessible web space from my old CIX-SUT account.

MC

[ffutures.livejournal.com]

Sorry - I missed the bit about making the images accessible on-line and thought it was document space that you were talking about.

[drplokta]

Regular ftp is fiddly with firewalls. It's both outgoing and incoming. You start an outgoing connection in order to log on, then the server opens a connection to you for the data transfer, rather than vice versa. Passive ftp gets round this problem, and if Transmit has that as a configuration setting, try it out.

[major-clanger.livejournal.com]

Transmit claims to use passive ftp by default. Nonetheless, I tried enabling inbound ftp on both my router and OS X firewalls... still no joy.

MC

[autopope.livejournal.com]

Wot the Doc said ...

When you connect to a site via FTP, you are opening a control channel. Commands to change directory, list files, etc, all go through the control channel. But for actual file transfers, FTP (the protocol) specified that a separate active connection initiated from the server end should be established (so that control over the session could be maintained via the control channel even while a file transfer was occuring over the data channel). Obviously, if a server tries to open a separate socket to your laptop the firewall is going to block it.

To deal with this problem, FTP also permits "passive" connections, in which the data is sent via the control channel. In the command line FTP client, you can use the -p command line flag (at least, the OS/X version of ftp(1) supports this). Or hunt for a suitable setting in your GUI program.

One thing gives me cause for concern: the OS/X command line FTP client defaults to passive connections these days, by design. This bears some digging ...