to resolve this issue we have to send a command to the server using the 'quote' command. Hence if you type:
i have instaled vsftpd server but i get this when uploading or dowloading files:
425 Use PORT or PASV first.
The FTP server wants to know whether to use a port-mode channel or passive-mode data channel. Most clients will set this up for you transparently (and generally choose passive 'cos it's newer and better)
remotehelp show you other commands that can server recive