what ports are used by ftp over ssl? [duplicate]
Solution 1:
Because FTP utilizes a dynamic secondary port (for data channels), many firewalls were designed to snoop FTP protocol control messages in order to determine what secondary data connections they need to allow. However, if the FTP control connection is encrypted using TLS/SSL, the firewall cannot determine the TCP port number of a data connection negotiated between the client and FTP server.
Therefore, in many firewalled networks, an FTPS deployment will fail when an unencrypted FTP deployment will work, but this problem can be solved with the use of a limited range of ports for data and configuring the firewall to open these ports.
via Wikipedia ... http://en.wikipedia.org/wiki/FTPS
Solution 2:
I was once greatly embarrassed by recommending FTP over SSL, assuming that the protocol had solved the design issues that plague FTP since the encryption would make them unsolvable. Instead, the encryption makes it impossible for a firewall to handle them!
FTP over SSL is sadly a useless protocol in the real world, where both ends will have a firewall in the way.