FileZilla Server 425 Can't open data connection for transfer of "/"
Solution 1:
You have most probably not opened the data connection ports on the firewall of the server (or have not forwarded the ports on NAT, if there's any).
Check what ports the FTP server is using and open/forward them.
Another problem is, that you have not configured a correct external IP address in the FTP server.
The FileZilla client can workaround that:
Server sent passive reply with unroutable address. Using server address instead.
But it's just a heuristics, that not all FTP client will do. So make sure you fix this too, even if it is not the immediate problem you have.
See the External Server IP Address for passive mode transfers section in the above screenshot.
See my article on network configuration for FTP for some background.
Solution 2:
The answer below derives from filezilla wiki:
https://wiki.filezilla-project.org/Setting_up_your_Router_to_Fix_the_%22425_code%22
3 steps in summary:
- Setup passmode port range.
- Create port forwarding rule on your router.
- Create a rule on your windows firewall to enable traffic in/out from your ftp server.
Details below:
(000042)3/3/2017 1:46:16 AM - admin (xxx.xxx.xxx.xxx)> 227 Entering Passive Mode (172,16,1,9,27,5)
(000042)3/3/2017 1:46:16 AM - admin (xxx.xxx.xxx.xxx)> MLSD
(000042)3/3/2017 1:46:26 AM - admin (xxx.xxx.xxx.xxx)> 425 Can't open data connection for transfer of "/"
According to the log messge from the 3rd last line
Entering Passive Mode (172,16,1,9,27,5)
The port used in passmode is 27*256+5 = 6917
Step 1, Setup Filezilla server passive mode:
This setting can be seen from [settings] > Passive mode settings
In my case is 6000-6100
Step 2, Router port forwarding setup:
Since you are routing the public IP to that server, you then need to create a port forwarding entry on your router according to that port range:
Step 3, windows firewall:
Next, check if your windows firewall has a rule to allow traffic from your filezilla program, if not then create one
