500 Syntax error, command unrecognized

[Valderos]

I setup the Filezilla server component according to the documentation methods. I can connect to the FTP internally. I can connect to the FTP server remotely using the Microsoft command prompt FTP commands or using Windows Explorer. However, when attempting to connect using the FileZilla FTP client, I get the following:

Code: Select all

Response:  230 Logged on
Status:      Connected
Status:      Retrieving directory listing...
Command:  PWD
Response:   257 "/" is current directory.
Command:   TYPE I
Response:   200 Type set to I
Command:   PASV
Response:   227 Entering Passive Mode (64,186,173,237,195,82)
Command:   MLSD
Response:   500 Syntax error, command unrecognized.
Error:          Failed to retrieve directory listing

I have configured the ports for passive mode, and opened the ports on the firewall. The firewall log is not showing any blocked traffic.

Any thoughts?

[boco]

Command: MLSD
Response: 500 Syntax error, command unrecognized.

That response is not from FileZilla Server. FileZilla Server fully supports the MLSD command. Seems like the firewall (or another device/software) doesn't support MLSD and returns an error in lieu of FileZilla Server. The problem is that it forgot to remove it from FZ Server's FEAT response.

One possible solution would be to use a listening port different from 21. Another one is to always connect using TLS.

[Valderos]

Thanks for confirming that for me. It pointed me in the right direction.

The Firewall had some component on there that would allow the initial control connection, but would block the data connection.

Its working great now!