Chapter 18. Securing your system

Procedure

1. To update your system, run the following command as root:

   # yum update

2. Even though the firewall service, firewalld, is automatically enabled with the installation of Red Hat Enterprise Linux, there are scenarios where it might be explicitly disabled, for example in a Kickstart configuration. In that scenario, you re-enable the firewall.

   To start firewalld, run the following commands as root:

   # systemctl start firewalld
   # systemctl enable firewalld

3. To enhance security, disable services that you do not need. For example, if your system has no printers installed, disable the cups service using the following command:

   # systemctl mask cups

   To review active services, run the following command:

   $ systemctl list-units | grep service