FTP problem

[hjm357]

I have what I hope is a simple problem. My work has setup an FTP site on their server where I can upload files. I can access this site from other computers, but not from mine. My computer is running Win XP Pro with SP2

I am using WS FTP Pro, and I get the error message "no socket".

I also tried to access it through internet explorer, and while I do not get an error message, nothing happens at all.

I am wondering if this has something to do with the security settings of SP2. I disabled the included firewall, but do not know what else to check.

Does anyone have any thoughts?

Thanks

[Sid]

Couple of things to check. Run a port scan to see if the at least port 21 is open. Both ports 20 and 21 should be open, if 20 is closed try setting the ftp client to passive mode.

[hjm357]

i ended up getting it to work with a different FTP client. i'm still at a loss as to why the other didnt work

[richardc]

In addition, you could try FlashFXP for here
http://www.flashfxp.com/
to see if it is the ftp client and not the server settings itself.

I soemtimes run up against sites where one will work and the other won't.

[TonyT]

It's probably something simple like what type of FTP connection to use. For instance, if use dsl connection, then passive mode ftp must be used. There's a setting in Internet Options\Advanced Tab for this. Some ftp clients can auto-detect your internet connection type and auto switch to passive mode. Also, some ftp servers are setup to use passive mode regardless of your connection type.

[Sid]

if use dsl connection, then passive mode ftp must be used.

The connection type doesn't really matter. I'm on DSL and my ftp users need a standard connection. Now some ISP's may block port 20 but being DSL doesn't make a difference.

[TonyT]

The connection type doesn't really matter. I'm on DSL and my ftp users need a standard connection. Now some ISP's may block port 20 but being DSL doesn't make a difference.

It does make a difference to those who are connecting, not those who are hosting the ftp server. Normally, if use dsl or have a firewall, passive mode must be used by the client to connect to the ftp server, unless the client side software firewall is configured to allow ftp or if the hardware firewall will pass through the ftp connection to the listening port.

***
http://slacksite.com/other/ftp.html
The main problem with active mode FTP actually falls on the client side. The FTP client doesn't make the actual connection to the data port of the server--it simply tells the server what port it is listening on and the server connects back to the specified port on the client. From the client side firewall this appears to be an outside system initiating a connection to an internal client--something that is usually blocked.

In passive mode FTP the client initiates both connections to the server, solving the problem of firewalls filtering the incoming data port connection to the client from the server.
***

The dsl issue is caused by the fact that many dsl modems don't support active ftp, and passive mode ftp must be use, and some dsl providers filter ports 20 & 21 too. Some dsl modems have an embedded non-configurable firewall, or a configurable firewall that cannot unfilter active mode ftp connections. This is because most isps use tftp to program the modems and active ftp is disabled in the modem itself, thus the only way to blow through the firewall is to use passive mode ftp..

[Sid]

Tony, I was going to go to no end to argue this point with you. Your first response made me stop and say whoa! I see what your saying about ISP's and their hardware locking down port 20 and I did suggest this in my first response. To state that all DSL users must use passive mode is simply incorrect.

[TonyT]

Tony, I was going to go to no end to argue this point with you. Your first response made me stop and say whoa! I see what your saying about ISP's and their hardware locking down port 20 and I did suggest this in my first response. To state that all DSL users must use passive mode is simply incorrect.

agreed

[Sid]

agreed