-4      Force IPv4 address resolution.

-6      Force IPv6 address resolution.

-8      Request 8-bit operation. This causes an attempt to negotiate the TELNET BINARY option for both
        input and output. By default telnet is not 8-bit clean.

-E      Disables the escape character functionality; that is, sets the escape character to ``no
        character''.

-K      Specifies no automatic login to the remote system.

-L      Specifies an 8-bit data path on output.  This causes the TELNET BINARY option to be negotiated on
        just output.

-X atype
        Disables the atype type of authentication.

-a      Attempt automatic login.  Currently, this sends the user name via the USER variable of the ENVIRON
        option if supported by the remote system. The username is retrieved via getlogin(3).

-b address
        Use bind(2) on the local socket to bind it to a specific local address.

-d      Sets the initial value of the debug toggle to TRUE.

-r      Emulate rlogin(1).  In this mode, the default escape character is a tilde. Also, the interpretation
        of the escape character is changed: an escape character followed by a dot causes telnet to
        disconnect from the remote host. A ^Z instead of a dot suspends telnet, and a ^] (the default
        telnet escape character) generates a normal telnet prompt. These codes are accepted only at the
        beginning of a line.

-S tos  Sets the IP type-of-service (TOS) option for the telnet connection to the value tos.

-e escapechar
        Sets the escape character to escapechar. If no character is supplied, no escape character will be
        used.  Entering the escape character while connected causes telnet to drop to command mode.

-l user
        Specify user as the user to log in as on the remote system. This is accomplished by sending the
        specified name as the USER environment variable, so it requires that the remote system support the
        TELNET ENVIRON option. This option implies the -a option, and may also be used with the open
        command.

-n tracefile
        Opens tracefile for recording trace information.  See the set tracefile command below.

-z option
        Set SSL (Secure Socket Layer) parameters. The default is to negotiate via telnet protocol if SSL is
        available at server side and then to switch it on. In this mode you can connect to both
        conventional and SSL enhanced telnetd's. If the connection is made to localhost and -z secure is
        not set, then SSL is not enabled.

verify=int  Set the SSL verify flags (SSL_VERIFY_* in ssl/ssl.h ).

cert=cert_file
            Use the certificate(s) in cert_file.

key=key_file
            Use the key(s) in key_file.

cipher=ciph_list
            Set the preferred ciphers to ciph_list.  (See ssl/ssl.h ).