Building a dynamic blacklist with Netfilter's Recent module
KEEP OUT!
Netfilter’s Recent module builds a temporary blacklist to keep intruders off your network.
When an Intrusion Detection System (IDS) recognizes an attack, it issues a strict “keep out” order to block the intruder’s access to services. Unfortunately, other systems on the network might not benefit from this block. The Recent module by Netfilter dynamically updates the firewall access rules to create a temporary “bad guy” list. You can then configure the firewall rules so that an IP address that breaks a rule is temporarily prevented from any form of access. Recent also comes with special features for fighting port scans, and you can combine the Recent module with an external application such as Snort to create a fast and effective framework for detecting and closing out network attacks.
Buy this article as PDF
(incl. VAT)
Buy Linux Magazine
US / Canada
UK / Australia
Subscribe to our Linux Newsletters
Find Linux and Open Source Jobs
Subscribe to our ADMIN Newsletters
Support Our Work
Linux Magazine content is made possible with support from readers like you. Please consider contributing when you’ve found an article to be beneficial.
News
-
KDE Unleashes Plasma 6.5
The Plasma 6.5 desktop environment is now available with new features, improvements, and the usual bug fixes.
-
Xubuntu Site Possibly Hacked
It appears that the Xubuntu site was hacked and briefly served up a malicious ZIP file from its download page.
-
LMDE 7 Now Available
Linux Mint Debian Edition, version 7, has been officially released and is based on upstream Debian.
-
Linux Kernel 6.16 Reaches EOL
Linux kernel 6.16 has reached its end of life, which means you'll need to upgrade to the next stable release, Linux kernel 6.17.
-
Amazon Ditches Android for a Linux-Based OS
Amazon has migrated from Android to the Linux-based Vega OS for its Fire TV.
-
Cairo Dock 3.6 Now Available for More Compositors
If you're a fan of third-party desktop docks, then the latest release of Cairo Dock with Wayland support is for you.
-
System76 Unleashes Pop!_OS 24.04 Beta
System76's first beta of Pop!_OS 24.04 is an impressive feat.
-
Linux Kernel 6.17 is Available
Linus Torvalds has announced that the latest kernel has been released with plenty of core improvements and even more hardware support.
-
Kali Linux 2025.3 Released with New Hacking Tools
If you're a Kali Linux fan, you'll be glad to know that the third release of this famous pen-testing distribution is now available with updates for key components.
-
Zorin OS 18 Beta Available for Testing
The latest release from the team behind Zorin OS is ready for public testing, and it includes plenty of improvements to make it more powerful, user-friendly, and productive.