On OS X it now goes smoothly with FileZilla and Netcup
Access to Netcup's webserver through FTPS finally works with Mac OS X and FileZilla.
Up to now I had to forbear from using the OS X version of the free ftp client FileZilla because access is provided only through FTPS by my hoster Netcup. This protocol, however, did not work with FileZilla on Mac OS X for a long time.
Research on the net led to shrug - I put the blame on Apple, put aside the topic and relied on pretty FTP client Cyberduck.
But these times are over!
Wether it was up to OS X Yosemite, the current Apple operating system and its handling of TLS connections or it was up to this specific version of FileZilla, i can not assess. The current tested FileZilla version 3.1.1. connects with Netcup's server (vsFTPd 2.3.2) with the settings shown in the screenshot below.
Examining the logs password and data transmission appears to go over an encrypted TLS channel:
Befehl: AUTH TLS Antwort: 234 Proceed with negotiation. (...) Befehl: PROT P Antwort: 200 PROT now Private.