I have a question regarding the ports used by the FTP protocol. We are supposed to upload some files and download some other files on a remote server, using the FTPS server. The remote server is listening on port 2121 but our connection is denied. Using a network sniffer, we determined that a whole array of other ports are used, such as 5590, 5109, 5246 or 5078. These requests are denied because our client is restricting the access on these ports. We use the WinSCP with the following settings: FTP Mode is Passive, the FTP Secure Mode is Explicit TLS and true for accepting TLS Host Certificate.
Our client is asking us to provide a list of ports that they should open for our access. How can we give them such a list of ports, when we such a wide range of values being used?
Any suggestions would be highly appreciated.