Editing FTP over TLS (section)

== Explicit vs Implicit FTPS ==
FTPS (FTP over TLS) is served up in two incompatible modes. If using explicit FTPS, the client connects to the normal FTP port and explicitly switches into secure (TLS) mode with "AUTH TLS", whereas implicit FTPS is an older style service that assumes TLS mode right from the start of the connection (and normally listens on TCP port 990, rather than 21). In a FileZilla client this means prefixing the host with "FTPES://" to connect an  "explicit" FTPS server, or "FTPS://" for the legacy "implicit" server (for which you will likely also need to set the port to 990).