참고 자료
Disabling direct root login

　To disable remote login access for your root user, edit the /etc/security/user file. Specify False as the rlogin value on the entry for root.

BATO-PC@root:/etc/security/> vi user

*
* rlogin        Defines whether the user account can be accessed by remote
*               logins.  Commands rlogin and telnet support this attribute.
*               Possible values: true or false.
*

root:
        admin = true
        SYSTEM = "compat"
        registry = files
        loginretries = 0
        account_locked = false
        rlogin = false