 or off, respectively. Replay protection is on by default unless overridden by a configuration file. When it is on, OpenSSL will automatically detect if a session ticket has been used more than once, TLSv1.3 has been negotiated, and early data is enabled on the server. A full handshake is forced if a session ticket is used a second or subsequent time. Any early data that was sent will be rejected.</p>

</dd>
<dt id="tfo"><b>-tfo</b></dt>
<dd>

<p>Enable acceptance of TCP Fast Open (RFC7413) connections.</p>