Primary management of SELinux for Linux

SElinux, kernel-level hardened firewall, selinux[security enhanced Linux (Secure hardened Linux)], is a Mac that works in the kernel (Mandatory Access Control, An implementation of a mandatory access control system that explicitly indicates which resources a process can access (files, network ports, and so on). The purpose of the mandatory access control system is to enhance the ability of the system to defend against 0-day attacks (exploits that exploit the vulnerabilities that have not been exposed). So it is not a substitute for network firewalls or ACLs, nor is it duplicated in purpose.

For SELinux's popular understanding:
SELinux, which makes a sandbox for specific programs (which are also growing), has a security label for the files, which belong to different classes and can only perform specific actions, which specifies that an application sets up the files or directories that you can access.

The impact of SELinux on the system:

Label each file, non-homogeneous labels cannot access each other

Features that will affect some of the services

in general, disabled, after setup, need to restart the kernel to take effect

SELinux Management level
SELinux turned on or off
Vim/etc/sysconfig/selinux

650) this.width=650; "src=" Https://s4.51cto.com/wyfs02/M00/9D/C6/wKioL1mFu5Tw9U-TAACAA0XD-xg180.png "title=" Screenshot from 2017-08-05 20-35-12.png "alt=" Wkiol1mfu5tw9u-taacaa0xd-xg180.png "/>

Selinux=disabled off State
Selinux=enforcing Mandatory State
Selinux=permissive Warning Status

Getenforce View Status
Two run-level levels when SELinux is turned on

Setenforce 0 Warning Status

Setenforce 1 Mandatory State

View FTP Service open in SELinux via Setsebool-p Ftp_home_dir on to open related services

650) this.width=650; "src=" Https://s1.51cto.com/wyfs02/M02/9D/C6/wKioL1mFvTWxQiwJAACSXrgsj1Q265.png "title=" Screenshot from 2017-08-05 20-41-46.png "alt=" Wkiol1mfvtwxqiwjaacsxrgsj1q265.png "/>

Primary management of SELinux for Linux