active mode

[Lansend]

I have a Windows 2019 server with FileZilla FTP server in Active mode.
I can connect in Active mode using the FileZilla client and Windows Explorer in active mode & get a directory listing
I cannot get a directory listing with FlashFXP client, I believe I have followed all available instructions but no luck.
425 Can't open data connection for transfer of /
I am the server admin and do not need to FTP , the designer uses FlashFXP and needs to connect via FTP.
So I downloaded the trial to see what it takes to connect using FlashFXP

I have attached the logs from the FileZilla FTP server , as it shows both clients reaching the server. I can upload session logs too if required.
Please note with the FlashFXP client I tried both LIST & MLSD
I can make changes on the server except use Passive mode
Any help afforded would be greatly appreciated

[MxxCon]

When ftp client is in passive mode(sends PASV command), it asks ftp server for IP:PORT to which to connect for data connection.
When ftp client is in active mode it sends PORT command which tells ftp server to which IP:PORT it should try to connect for data connection.


Unless a user has a smart enough router that monitors and understand FTP connection's commands, or if FTP encryption is in play, they need to manually go into their router's configuration and manually forward a range of ports which would be used for FTP data connections. Then they also need to configure FlashFXP or any other FTP client to use that port range.


To save users the hassle of doing all that, server admins who are generally more savvy configure necessary things on their end and tell their clients to just use PASV mode.


Alternatively, switch to SSH/SFTP protocol which is both, encrypted and doesn't need any extra open ports to work. FlashFXP supports this as well.

[Lansend]

MxxCon , Thank you for your response.
As I indicated , I can connect in Active mode using the FileZilla client and Windows Explorer.
I have access to many other networks and could connect in Active mode using the FileZilla client and Windows Explorer.
Moreover I have many other servers with FTP in Active mode only and have not had any issues with FileZilla client and Windows Explorer.
Typically on routers /Firewalls , we configure outbound to be any any.
I have not had to NAT or forward port 22 to a specific IP.
It is my understanding that once an internal IP connects to an external IP ( regardless of protocol). Stickiness on the routers /Firewall kicks in and all traffic on any port is routed from that external IP address to the initiating internal IP address.

I dare say that this is some config issue in FlashXP
Will look into SSH/SFTP

Thank you

[MxxCon]

Port 22 is SSH port and I'm not sure what you mean by not having to NAT it.

FTP protocol uses 2 of ports. One port for control connection, often tcp/21, and another port for the data connection

You'd need to post session logs from both clients to see what they are doing different that doesn't work.

[Lansend]

Thanks MxxCon , we typically use 22 as the data port , active mode. If I am not mistaken , this has been default.

[MxxCon]

As far as I know that has never been a default port for that since 22 has always been SSH port.
On some clients and servers OUTGOING connection ORIGINATES on port 20. But that's a separate thing.


Data connection ports are usually on ranges above 1024 to allow unprivileged server user to create connections. Additionally, it's usually more than just a single port, but a range to support multiple user connections or simultaneous transfers.

[Lansend]

I stand corrected. The outgoing port 20 is open