FTP error 500 illegal port command

[Debbie Fleith]

After making some changes on our firewall, we can no longer send/receive files from our FTP server. We login just fine, so the port forwarding appears to be working. However, when we attempt to send or receive any files, we get the following error:
"500 Illegal PORT Command 425 Can't build data connection: Connection refused."
We also get the "500 Illegal Port command" error when we try to issue any other commands like ls.

Does anyone know what is wrong?

we get:

[Christopher McCray_1]

Hello,

Did these changes change the access into/out of the network via port 20(ftp_data)?

FTP uses port 21 for the connections, but data transfer is done over port 20.

Hope this helps

Chris

[Andrew Cowan]

Some firewalls also need specific configuration to enable "passive" ftp mode. You need to look closely at your firewall's documentation.