Windows – Network configuration for ftp server on LAN

ftpwindows

I am looking for a way to debug/diagnose the LAN on my work which consists of multiple subnets.

More specifically I am trying to find some good tools (windows/linux) that can give me info on which ports are open or which machines/networks are accessible from a given machine.

Currently I have installed a FileZilla FTP server on a virtual windows 7 machine hosted in vSphere. I have verified that the ftp server is running as a service and configured with a single user admin that has a single shared folder c:\test. But when I try to connect from my laptop the server log gives:

(000012)18-12-2013 15:46:28 - admin (172.22.74.144)> PWD
(000012)18-12-2013 15:46:28 - admin (172.22.74.144)> 257 "/" is current directory.
(000012)18-12-2013 15:46:28 - admin (172.22.74.144)> TYPE I
(000012)18-12-2013 15:46:28 - admin (172.22.74.144)> 200 Type set to I
(000012)18-12-2013 15:46:28 - admin (172.22.74.144)> PASV
(000012)18-12-2013 15:46:28 - admin (172.22.74.144)> 227 Entering Passive Mode (172,22,80,8,192,35)
(000012)18-12-2013 15:46:28 - admin (172.22.74.144)> MLSD
(000012)18-12-2013 15:46:39 - admin (172.22.74.144)> 425 Can't open data connection.
(000012)18-12-2013 15:48:39 - admin (172.22.74.144)> 421 Connection timed out.
(000012)18-12-2013 15:48:39 - admin (172.22.74.144)> disconnected.

I have tried reading this guide but cannot see what is needed:
https://wiki.filezilla-project.org/Network_Configuration

And here it says:

https://forum.filezilla-project.org/viewtopic.php?f=6&t=24925

that ftp used tcp, so do I need to forward some ports?

On the windows server I have tried to run netstat -an

which gives:

 TCP    [::]:21                [::]:0                 LISTENING
 TCP    [::]:135               [::]:0                 LISTENING
 TCP    [::]:445               [::]:0                 LISTENING
 TCP    [::]:3389              [::]:0                 LISTENING
 TCP    [::]:49152             [::]:0                 LISTENING
 TCP    [::]:49153             [::]:0                 LISTENING
 TCP    [::]:49154             [::]:0                 LISTENING
 TCP    [::]:49155             [::]:0                 LISTENING
 TCP    [::]:49157             [::]:0                 LISTENING
 TCP    [::1]:14147            [::]:0                 LISTENING

But don´t know how to interpret the above output.

I seems that I can telnet to the machine on port 21 telnet my-windows-server 21:

220-FileZilla Server version 0.9.41 beta
220-written by Tim Kosse (Tim.Kosse@gmx.de)
220 Please visit http://sourceforge.net/projects/filezilla/

Does that indicate that the port is open?

More generally what are the first things to check/verify when solving a problem like this?

Best Answer

Are your subnets filtered (ACL, firewall...) ?

The above output you are talking about shows you both listening and non-listening ports on your server in numerical addresses, with the interface they listen to (and protocol TCP/UDP).

To debug this, Telnet host port is a good starting point to check if a port is listening and open over the network, but will only works against a TCP port. In your case, yes, that indicates that port 21 is open.

You can also use nmap myserver to get a list of open ports for a given target host, it is also able to check UDP ports, and it runs on both windows and linux Os.

Also, i would use a network sniffer like tshark or wireshark at server side to see what is happening.

Note that there is 2 FTP modes : Active or Passive :

  • Active mode uses port TCP/21 for controls and port TCP/20 for datas (ports are fixed).
  • Passive mode uses port TCP/21 for controls and any TCP port between 1024 to 65534 for datas. These ports are dynamic.

In your case, i think your problem has to deal with it. Regarding your error log seems you are in passive mode.

I would try Active mode.

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