When you connect to an FTP server using the Windows NT or Windows 2000 command-line FTP client and issue a quote <command>, the next command that you issue may generate a 425 Can't open data connection error.
When an active mode FTP client passes a command to a FTP server, the client passes a port on which it listens for a server response. If the client sends a command that does not require a data port, it doesn't send one.
FTP clients can pass the server commands that they do not interpret. These commands use the quote <command> syntax. The client sends these commands without a listen port for the data, so the server generates the 425 error if a port is required.
The ls command requires a listen port, and therefore sends one. The Quote command doesn't send a port, so Quote ls generates a 425 error.
The Windows FTP client does not support passive mode, so it always needs to send a port when issuing a command that returns data.
The following are the valid commands:
Commands may be abbreviated. Commands are:
! delete literal prompt send
? debug ls put status
append dir mdelete pwd trace
ascii disconnect mdir quit type
bell get mget quote user
binary glob mkdir recv verbose
bye hash mls remotehelp
cd help mput rename
close lcd open rmdir