The relatively vast content of this chapter may appear overwhelming. A key takeaway should be the focus on the frameworks (modules). If we're discussing firewalls, we should look at packet filtering frameworks such as
nftables. For access control, we have security modules such as SELinux and AppArmor. We covered some of the pros and cons of each. The pivoting choice, possibly deciding the Linux distro, is between AppArmor and SELinux. One is perhaps swifter than the other, with the related administration effort hanging in the balance. For example, choosing AppArmor would narrow down the major Linux distributions to Ubuntu, Debian, and OpenSUSE. The distro choice, in turn, would further dictate the available firewall management solutions, and so on.
Mastering the application security frameworks and firewall management tools will help you keep your systems safe with minimal effort. As with any typical Linux system administration task, there are...