During the initial connection handshaking process clients send an ordered cipher suite list to use for the duration of the connection. The server selects a cipher suite from the client's preferred order list of supported cipher suites.
By default, because the TLS honor server cipher list option is checked in a listener's SSL Options or the MF Directory Server tab, the conversation will use the server's preferred protocol and cipher suites list. If you have not specified a value for the TLS protocols or Cipher suites fields, then the default is used. The TLS protocols field now supports TLS1.3. See Configuring a TLS Protocols List and Configuring a Cipher Suites List for more information. You can use the TLS honor server cipher list to force the use of a strong, ordered list of protocols and cipher suites. This controls the strength of cryptography used between server and client.