June 2025
Beginner to intermediate
1180 pages
37h 48m
English
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29.5 Custom Firewall Built Using nft
This section contains two small examples to show that creating simple firewalls is by no means witchcraft. The examples are intended for anyone who wants to better understand and experiment with firewalls.
Warning
I don't want to give the impression with this section that you can replace professional firewall tools with your own 20-line or 30-line scripts! On the contrary, I advise that you use the firewall tools of your distribution or use distribution-independent firewall configuration tools.
29.5.1 Nftables: Basic Principles
Basically, a packet filter firewall works as follows: Network packets reach the kernel via interfaces. The kernel decides what should happen to the packets on the basis of ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.