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F430

@qwest.net

Why does suddenlink block client ftp?

Ever since Suddenlink bought my local cable ISP the service has been going down hill. It has gotten so bad that I added DSL so now have two ISPs. Since November I have been unable to copy files using an ftp client on my PC when I am plugged into the Suddenlink modem. If I plug the PC into the DSL modem everything works fine.

Why is Suddenlink blocking my ftp downloads?

I tried switching to http downloads but that doesn't work for files over 200 Mbytes. Suddenlink starts blocking the download at about that the 190 - 200 Mbyte point and eventually my browser reports a timeout. Again DSL works fine.

I like having two ISPs for my PCs. Is there any way to get a reliable connection from Suddenlink or should I just give up and go back to a single ISP (DSL)?



shelby10763

join:2005-03-12
Greenville, NC

I've never had any issues with ftp clients or http downloads. Do you have issues with any other sources?



F430

@qwest.net

I think it is specific to my area. Watching uTube is painful - watch a few seconds and then wait 15 - 30 seconds for "buffering", then another few seconds and the same thing. HD videos will not start at all. No problems with uTube on DSL. I asked a neighbor last night and he said they dropped cable for this very reason. Sounds like I have to do the same.



moldypickle

join:2009-01-04
Haughton, LA
kudos:2

After you explain it that way it sounds like you have a bandwidth issue, not a port blocking issue.

Can you just post up a quick test from speedtest.net please and that will give us a little more light on the subject.



SDL L3Tech

join:2011-06-07
Tyler, TX
kudos:28
reply to F430

We do not block FTP on our network in any region. Is the FTP server ping-able and if so are you able to ping it? If it is ping-able and you're not able to ping it, please run a trace-route to it.

Also, please PM me your cable modem's MAC address, you're public IP (»whatismyip.com), and the FTP server you're connecting to so I can further look into this problem.



Chubbzie

@nc.us
reply to F430

If you cannot download files over 200MB via HTTP that is either a configuration limit on the web daemon you are downloading from or a browser/client/bandwidth issue. You might want to try a download manager/accelerator to see if that alleviates this problem. Multi-threaded downloads over HTTP tend to work a bit better in my experience.

Are you actually attaching to the FTP server while on SL's network or is it just timing out all together? Is it possible that the FTP daemon has been configured to block or rate limit based on your IP or IP range? You can also telnet to the FTP server and issue commands manually to try and troubleshoot...



F430

@cox.net
reply to SDL L3Tech

quote:
Is the FTP server ping-able and if so are you able to ping it?
Yes and yes. As I stated if I switch the ethernet cable from the Suddenlink modem to the DSL modem it works fine. The two modems are sitting next to each other so it is easy to switch the cable. DHCP on the Windows PC then gets a new IP address as expected and I am able to browse.


F430

@cox.net
reply to Chubbzie

quote:
If you cannot download files over 200MB via HTTP that is either a configuration limit on the web daemon you are downloading from or a browser/client/bandwidth issue.
Interesting that you make that claim since DSL works fine. As described in my previous posts I have two modems. One Suddenlink and one DSL. Plug the PC into the DSL modem and all works fine. Plug the ethernet cable into the Suddenlink modem and downloads atop at 200megabyte. I even tried the same files. Fail on Suddenlink. Work fine on DSL.

quote:
Are you actually attaching to the FTP server while on SL's network ...
Yes. list and other commands work fine. When I ask the server to send me a file (GET command) the server tries to do so (PASSIV mode) and times out.


Chubbzie

@suddenlink.net

Hmmm, quite odd. Did you also try an active ftp transfer? So all of your commands over port 21 work fine but when you initiate an actual data transfer over port 20 it just times out. What happens if you try and upload to the server?



SDL L3Tech

join:2011-06-07
Tyler, TX
kudos:28
reply to F430

If you're able to connect and run commands then that proves we're not blocking the standard FTP port of 21. Since it is running in passive mode then that eliminates port 20 as well since it should randomly pick ports within the configured passive range.

As Chubbzie stated, please try it in active mode and see if you can get it to work that way. It would also be helpful for you to post the FTP logs on the SDL connection and the non-SDL connection so we can see the ports it is trying to use for the data transfer.



Chubbzie

@nc.us

Whoops, forgot we were talking about PASV mode with dynamic port enumeration. Should've had my coffee first...



moldypickle

join:2009-01-04
Haughton, LA
kudos:2

Rereading the post, I hope you're not using your browser as your ftp client.



F430

@cox.net
reply to SDL L3Tech

Sorry about not responding sooner. I am travelling on business. I should be back by the end of the week and will get the logs of the FTP sessions then. I'll also try active mode.

Thanks.