Recently I´ve known that my ISP has blocked ports for connections towards port 21 for any clients on it´s network. I had an ftp server and it worked really fine. But with this new policy, I had to change the port.
So I changed the services file in /etc/ and changed ftp port 21 to 40740. Ok it receives connections normally. It authenticates users nicelly but keeps giving me this message when I type dir, for example...
500 Illegal Port Command.
425 Use PORT or PASV first.
It works neat from my Lan anyway. This problem only occurs when I try to entre the FTP through WAN.
Thanks a lot!