Limiting and Monitoring Superuser

Your system requires a root password for superuser mode. In the default configuration, a user cannot remotely log in to a system as root. When logging in remotely, a user must log in with the user's username and then use the su command to become root. For security reasons, 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 Superuser.