Your system requires a root password for superuser access. In the default configuration, a user cannot remotely log in to a system as root. When logging in remotely, users must log in with their user name and then use the su command to become root. You can monitor who has been using the su command, especially those users who are trying to gain superuser access. For procedures that monitor superuser and limit access to superuser, see Monitoring and Restricting root Access.