I'm aware of the following:
- I can disable access to port 21 via the firewall
- I can disable access to non-ssl connections to users in the admin interface of FileZilla
- I can restrict access to the server by IP via the firewall
all of which I've done already.
However, is it possible to completely switch off port 21? I only want to enable FTP over SSL and not standard FTP on port 21 regardless of the above points.