I'm after a server side FTP client to get around an issue with an ISP's proxy server. My Dad uses the ISP Blueyonder and one website he uses can only be seen if he uses blueyonders webcache proxy server (why I don't know) but his FTP program does not work when the proxy settings are entered and can not even access the site without them.
So a server side FTP client would work but needs to be....
1) PHP / CGI Based
2) Does not use any Java Applets
3) Allows the basic upload / download and delete
4) Hopefully has the standard dual window pane view
Any linkies would be appreciated :)
1) Have you tried going directly to the IP address rather than the domain name? (in case there's bad info in the DNS server you're getting
2) Have you tried using passive FTP instead of active FTP? There's a switch in most FTP programs that lets you pick one mode or the other. Most proxy servers will not work properly with active FTP.
1) Have you tried going directly to the IP address rather than the domain name? (in case there's bad info in the DNS server you're getting
IP address does not work either and only works when going through blueyonders proxy.
2) Have you tried using passive FTP instead of active FTP? There's a switch in most FTP programs that lets you pick one mode or the other. Most proxy servers will not work properly with active FTP.
Woot!, success. Passive mode did the trick and it now works a treat. I never knew what passive mode was for.
Many thanks for that tip. Another little tip to add to the brain cells, thanks :)
FTP is a bit weird, compared with most other server communications. It uses a command channel, and a data channel.
With active FTP, the client establishes a connection to port 21 on an FTP server. The FTP server in turn will respond by creating a data channel, and connect it to a random port on your computer. It will sent the info on what port to listen to over the control channel, so your FTP program knows where to look and how to answer.
When you connect through a proxy server, that means that the FTP server will initialte a connection to a random port on the proxy server itself, which will promptly drop it since it does not expect any incoming traffic there, and has no idea who its for -- meaning your FTP connection won't work.
Passive FTP is a little different, in that it will communicate back to the client what port to use for the data channel, and then the client will establish the outgoing connection to that port, rather than having the server initiate it. From the proxy server's point of view it is just another outgoing connection, which it can facilitate without problem.
If you have a 'smart' proxy server that actually snoops inside the packets and analyzes the content, they can detect that you are trying to initiate an active connection, and patch through the server established data channel when it comes in... but that's a lot more resource intensive, and the vast majority of proxy servers can't/won't do that... But passive FTP is an easy work-around. Historically active FTP has been the standard, hence the problem with proxys...
I was guiding him over the phone how to set his FTP up via the proxy server that bluyonder needed in this case but the active/passive connection never dawned on me at all. I've seen the options for it before but on my ISP both work fine so just dismissed it as some servers may require one of the other.
Thanks once again :)