Learning RHEL Networking

Understanding SELinux

Let's start pulling the covers off SELinux and discover a little more about what makes these controls work, starting with SELinux modes.

Modes

To begin with, we will discuss three modes that we can run with SELinux. These modes are illustrated for you in the following figure:

The disabled mode

When SELinux is disabled, SELinux is not used and the objects are NOT labeled. In the disabled mode, we rely solely on the original DAC. If we later need to enable SELinux, the boot process is lengthened because all the objects need to be relabeled again. Disabling SELinux completely like this is probably not a good idea, but should it be ...