FTP Upload Connection Dropout
 

I have been trying to upload a 50MB file via FTP under OSX and my connection keeps dropping out after uploading about 2.8MB. I resumed the upload and it dropped out again at 5.6MB and continued like this for the whole upload after which the file was corrupt ( no big surprises there ). I have tried CyberDuck which was getting a broken pipe error. I tried curl from Terminal and no joy there. I tried a Director app which also stalled. I tried turning off the firewall which didn't help. I rebooted into Win XP under BootCamp and was able to upload the file in one go from a command window with the ftp command. Any ideas? What do I need to do to ftp from OSX?

You might try adjusting Cyberduck's connection preferences. The default appears to wait ten seconds and only retry once. That may not be enough for large files over your connection.

CyberDuck is set to 5 retries but I'm not sure CyberDuck is the issue if curl failed as well. Why was I able to FTP from XP using the same connection? Is there something about FTP that can cause my DSL to drop out? Basically my connection is always on unless I try to upload from OSX. Checking my stats on my connection it drops out after 2-3MB of upload and reconnects 8-10 seconds later. It's the actual DSL connection that drops out not the connection to the site I'm uploading to.

Maybe your MTU is a little high for DSL.

A few sites showing problems with MTU settings:

http://www.cisco.com/en/US/tech/tk17...80093bc7.shtml

http://forums.speedguide.net/showthread.php?t=199883

http://www.broadbandreports.com/foru...aking-MTU-Help

http://www.dslreports.com/faq/5793

Hmmm. You could be right. My modem was configured to 1500MTU. I dropped it to 1492 and it got to 7.0MB before dropping out. Hopefully if I keep tweaking it will get there. Thanks CWT, this has been driving me nuts.

I've had trouble with Cyberduck on some servers to the point that I don't use it at all anymore. Which is sad, because I really liked it. Moved on to Transmit. Have you tried that. There is also an ftp plug in for firefox that works quite well if your a firefox user. The name escapes me at present. I'll look around and post back when I find the name.

When I have my optimal MTU do I need to set it in my network preferences as well as my modem or do I just set my network to automatic?

Also why is XP able to use the connection without dropping out?

I'd set it in the network preference.
It could be that XP is already set to a lower MTU.

Are you using a router?

I'm plugged into my modem via ethernet but it's described as a router on the help page

iConnect 622

I've never seen a software 'Wizard' that impressed me. First, they're almost always (never seen one that wasn't) written for PCs and ported to the Mac. Second, they try to set up your Mac as if it were a PC. Third, they use settings that should work okay for most systems so they aren't optimized for any of them.

I'd go through everything from DNS settings to Ethernet (configure Manually, hopefully at 100baseTX, Full-duplex) and I'd check out proxies for anything strange.

Yeah that wizard didn't get past authentication and I had major teething issues. They had to change my line at the exchange a number of times before I got a connection that would authenticate reliably.

I tried pinging to find my optimum MTU and had no fragmentation at 1500 but I read that XP uses 1480 so I guess I'll try that.

What does 100baseTX, Full-duplex apply to? I was poking around my modem configuration and couldn't find anything that related.

100baseTX is your transmission speed over ethernet. Most modems/routers don't yet go to 1000 (gigabit) but they can go to 100 megabit, so you usually want that.

Duplex refers to when the parties can talk. Half duplex means that one side talks, the other listens. Full means they can both transmit at the same time.

Oh ok. I haven't exactly got a premium account so I don't think my connection speed is going to overtax the modem. Just downloading the user's guide for my modem.

Thanks for the input.

The 100BaseTX is the communication between your computer and the modem's router port(s). It shouldn't affect the modem/ISP connection, unless it's having problems. If it's faster than the modem, that's fine. If for some reason it's slower or error prone, that could cause trouble.

Oh yeah, there it is. I've got my Ethernet set to configure automatically. How would I work out what it's chosen? Or should I just set it? Basically four days a week I work from home and one day a week I go into the office and hook up to a windows network.

I always set it manually. I don't have any proof, but it seems to be more prone to trouble with automatic. Is the Windows network (1000baseT) gigabit? If so, you'd want to change it when there, but even that can be taken care of with a new network location.

So I'm down to 1180 MTU and still dropping out. Looking at the modem my ethernet and DSL lights blink indicating transmission but it gets to 4 and a bit MB and the lights stop blinking followed by my internet light switching off and back on a few seconds later as it reconnects. Am I wasting my time to continue dropping the MTU? What else should I look at? It never drops out unless I'm uploading. I need to upload a 400MB disk image for someone in the states tomorrow.

It could be your internet connection. How far are you from the phone company's CO? DSL speed and reliability drop off with distance, and you may be close enough that it works ok because error correction works with small chunks of data. With large files though, those errors are more likely to cause a time out.

Well, I'm semi-excited.

I never got anywhere with my MTU settings and have just been putting up with drop-outs in OSX or FTPing through Windows XP command line.

I set my MTU settings back to where they started and tried the connection speed setting in Cyberduck preferences and set it to the next setting below my maximum upload connection speed and was able to upload 35MB without a drop out. Yay.

thx for ur help and now i can upload files of bigger sizes:o