Can't connect to ISP's FTP server. What's wrong?

Gullible Jones · 2011-09-11 01:07:33

For the past six months I have been completely unable to connect to my ISP's FTP server. I can connect to any other FTP server; but not my ISP's.

I've tried opening various ports on my router. I've tried putting the client computer in a DMZ, completely open to the internet. I've tried logging in from different locations with service provided by different ISPs. No matter what, the FTP client just hangs for a while and then times out. It matters not what configuration, what port, or what operating system.

The ISP swears the problem is on my end, not theirs.

Is there something I've overlooked, or is the ISP in fact at fault?

lifeafter2am · 2011-09-11 02:55:02

Gullible Jones wrote:

For the past six months I have been completely unable to connect to my ISP's FTP server. I can connect to any other FTP server; but not my ISP's.
I've tried opening various ports on my router. I've tried putting the client computer in a DMZ, completely open to the internet. I've tried logging in from different locations with service provided by different ISPs. No matter what, the FTP client just hangs for a while and then times out. It matters not what configuration, what port, or what operating system.
The ISP swears the problem is on my end, not theirs.
Is there something I've overlooked, or is the ISP in fact at fault?

Sounds to me like you have a lot of evidence to support that it's something on their end.

ewaller · 2011-09-11 05:41:33

Gullible Jones,
Just to provide a quick summary of our PM conversation to keep the forums "in the loop"
The address of your ftp server had the 'ftp.' subdomain prepended to the URLs domain name. You had also indicated an alternative was 'user.' prepended to the domain name. Both of those timed out for me.

I did try dropping the 'ftp.' and used just the domain name and was able to connect and was then challenged for my credentials. See if that works for you.

R00KIE · 2011-09-11 11:31:32

Is that ftp server using passive or active connections? It may be a case of your router messing things up for you, the router I have now must be told in the application level gateway configuration that I want to use ftp, what it does is modprobe the ip_conntrack_tftp module.

I have found that without this active ftp connections don't work, it doesn't matter if I forward the needed ports or if I put the machine I'm using in the dmz.

Gullible Jones · 2011-09-11 11:40:09

ewaller wrote:

Gullible Jones,
Just to provide a quick summary of our PM conversation to keep the forums "in the loop"
The address of your ftp server had the 'ftp.' subdomain prepended to the URLs domain name. You had also indicated an alternative was 'user.' prepended to the domain name. Both of those timed out for me.
I did try dropping the 'ftp.' and used just the domain name and was able to connect and was then challenged for my credentials. See if that works for you.

Ah, I forgot to mention that. That's not the correct FTP server; it rejects my credentials.

ROOKIE: hadn't tried that, thanks. But it seems not to work either.

R00KIE · 2011-09-11 13:33:26

If you are using a firewall in your machine it might help to modprobe nf_conntrack_ftp so that accepting related connections works (which is the case with active ftp connection).

Passive connections should always work as far as I know so you could try forcing a passive connection, that is no falling back to active connection, and vice versa.

If nothing works then I'd say that the probability of the problem being on the ISP side is higher than the problem being on your side, but who knows, maybe some pesky detail is ruining the fun for you.

ewaller · 2011-09-11 15:58:20

I too feel this is the ISP side. For fun, I took my router out and connected directly to my DSL modem. My ISP does not block any ports except for 25 ( and they will open that on request) Still no joy.

Gullible Jones · 2011-09-11 19:38:46

Thanks guys... I thought as much, but I just wanted some independent confirmation.

Arch Linux

#1 2011-09-11 01:07:33

Can't connect to ISP's FTP server. What's wrong?

#2 2011-09-11 02:55:02

Re: Can't connect to ISP's FTP server. What's wrong?

#3 2011-09-11 05:41:33

Re: Can't connect to ISP's FTP server. What's wrong?

#4 2011-09-11 11:31:32

Re: Can't connect to ISP's FTP server. What's wrong?

#5 2011-09-11 11:40:09

Re: Can't connect to ISP's FTP server. What's wrong?

#6 2011-09-11 13:33:26

Re: Can't connect to ISP's FTP server. What's wrong?

#7 2011-09-11 15:58:20

Re: Can't connect to ISP's FTP server. What's wrong?

#8 2011-09-11 19:38:46

Re: Can't connect to ISP's FTP server. What's wrong?

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