I recently bought a Bambu A1 Mini 3D printer to try out 3D printing. This printer offers a FTP server, allowing users to use FTP clients like FileZilla or WinSCP to upload model files for printing, and download timelapse videos. However, when I tried connecting to the printer with FileZilla, I found that although the username and password were correct and login was successful, I couldn't retrieve the file list: Some users on the Bambu official forum have also reported this issue, such as this reply and this reply . Some users mentioned that WinSCP works , but I use Linux daily and don't want to switch to Windows just to connect to the printer's FTP service. So I investigated the cause of the problem and found a solution for Linux. Introduction to FTP Protocol To understand this problem,...