Problem

When there is a Cisco ACE load balancer between SecureClient and the server to which you are connecting, the Cisco ACE breaks the FTPS connection with errors similar to the one below:

"Possible PASV port theft, cannot open data connection."

Resolution

As per Cisco's support team, the Cisco ACE does not work with FTPS passive mode, unless all outgoing ports are enabled. The suggested workaround is thus to bypass the Cisco ACE and open all ports.