I'm trying to conect to my suppliers FTP server with user and password. I can connect perfectly using normal FTP tools like MacOS' Finder, Filezilla, etc, but for some reason I can't get RClone to connect to the server.
What is your rclone version (output from rclone version)
Thanks for the suggestion, I hate using FTP in any situation. Unfortunately I'm connecting to the classic "Enterprise" what uses tools from the dark age...
I ran the command with the debug flags you suggested. It seems like an issue with the Go FTP client not supporting the "229 Entering Extended Passive Mode (|||18608|)" command?
This looks like a firewall or network issue; in passive mode the client (rclone) attempts to connect to the server on a port the server has requested (in the second example it was port 18608). rclone attempts to connect to that... and fails.
rclone can act as a sftp server using rclone serve sftp.
if you can open a port on the router in front of the server, then you can run rclone serve sftp.
The issue seems to be ftp.myprovider.com's firewall blocking the ports used by the Extended Passive Mode. Seeing that the port was received after issuing the EPSV command, I searched the rclone documentation and found the option --ftp-disable-epsv. Running the command with this flag fixed the connection.
Thanks everybody for pointing me in the right direction!
Unfortunately I have no control over the server, so cannot ask them to open ports, upgrade to a secure protocol or any other true fix, but this will have to do!
My guess is they have a "dynamic" firewall with "helper" functionality; it sees the PASV command response and temporarily opens the necessary port so you can connect to it (Or they may have NATting from their border to the internal machine, especially if there's a cluster behind it, or a load balancer or.... many reasons). Linux iptables can do this, for example, with the ftp helper.
Since EPSV is newer and the output format is different (no IP address) it doesn't know how to parse it and so isn't able to allow your connection through.