Some doubts with port forwarding and active mode.

Hello.

I have a doubt about the WinSCP configuration.

I have a device with FTP server. I dont have access to ftp server configuration in this device. Its a industrial equipment. This device is connect in a local network and has ip address 192.168.1.16.

This device is connect to a PC with Windows. This PC has 2 network interfaces. One interface to local network (ip 192.168.1.30) and other to corporative network (ip 10.17.10.5).

A second PC with Windows has only interface to corporative network (ip 10.17.10.20) and I need that this PC have a FTP client and connect to FTP Server in the device in local network.

I installed a Port Forwarding (I'm using DoorPointer) in the PC with 2 network interfaces. When this PC receive request in port 5028, it redirects to 192.168.1.16 on port 21.

So, the FTP Client can connect to FTP Server. No problem for it. But when I need to send LIST command I receive error.

I think need to configure the FTP connection to active mode and just one specifical port for data connection. I think this is because I need to configure on Port Forwarding a specifical port to return the data to second PC.

Follows my configuration in DoorPointer:
From Port | To Host | To Port
---------------------------------------
5028 | 192.168.1.16 | 21
1024 | 10.17.10.20 | 1024

In the case, I configured the port number 1024 for data connection. So, the FTP Server send the data through port 1024.

I tested with FileZilla Client and it works. But in WinSCP I cannot configure a specifical port for data connection and I belive that it is necessary because I need to use the Port Forwarding.

I want use WinSCP because I can write automatical scripts.

Can you help me?

WinSCP cannot limit ports it uses in the active mode.
But why do you even use the active mode? Why don't you use the passive mode?

martin wrote:

WinSCP cannot limit ports it uses in the active mode.
But why do you even use the active mode? Why don't you use the passive mode?

Hello, martin!

In passive mode the FTP Server choose a random port to data connection, right? I would need use this port on Port Fowarding software. But, in this mode, the port is random. I cannot redirect a random port. So, I need use active mode for have a specifical port to redirect.

How do I do?

lucasrr84 wrote:

In passive mode the FTP Server choose a random port to data connection, right? I would need use this port on Port Fowarding software. But, in this mode, the port is random. I cannot redirect a random port. So, I need use active mode for have a specifical port to redirect.

I do not follow. In the active mode the port is also randomly chosen, only by the client. That's the problem you have with WinSCP in the active mode, right? That the port is random.

Did you solve it with FileZilla by restricting the active mode port range to a single port? So you can do the same for the passive mode, but on the server side.

Btw, active mode port range request is here:
https://winscp.net/tracker/958
(you can vote for it, if you want to get it implemented)