3.1.5.3 REIN Message Handling

A client can send a REIN message over a session negotiated with Implicit FTPS. The server responds with a reply as specified by [RFC959] and then shuts down the TLS session.

At the end of the REIN message, processing the client MUST restore the internal state for the connection to the same state it was when the original TCP connection was established. If the client is to reuse the TCP connection, it MUST negotiate the Implicit FTPS again.