How To Install nftables In Ubuntu

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firewall2-image

In this article, we will learn how to switch a Linux firewall from IPtables to nftables on Ubuntu. IPtables, which is based on the Linux kernel Netfilter module, is currently the default firewall for many Linux distributions. It protects against multiple threat vectors and allows your server to block unwanted traffic based on a specific ruleset.

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How to Set Up A Firewall Using Iptables on Ubuntu 16.04

Reading Time: 5 minutesThis guide will walk you through the steps for setting up a firewall using iptables in Ubuntu 16.04. We’ll show you some common commands for manipulating the firewall, and teach you how to create your own rules.

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How To Set Up Multiple PHP Versions in Webmin

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What is Webmin?

Webmin is a browser-based graphical interface to help you administrate your Linux server.  Much like cPanel or Plesk, Webmin allows you to set up and manage accounts, Apache, DNS zones, users and configurations.  As these configurations can get somewhat complicated Webmin works to simplify this process. The result is fewer issues during server and domain setup.  Which results in a stable server and a pleasant administration experience. Unlike Plesk or cPanel, Webmin is completely free and open to the public. Unfortunately, here at Liquid Web, we do not offer managed support for Webmin, but we are always willing to assist as much as possible when issues arise.   You can download Webmin from their site. Also, you can find some excellent documentation on this interface.

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An Introduction to Firewalld

Reading Time: 5 minutesIn some ways, firewalld on systemd systems is easier to manage and configure than iptables. There are, for the most part, no long series of chains, jumps, accepts and denies that you need to memorize in order to get firewalld up and running in a basic configuration. The rules are simple and straightforward, but there is no reason you cannot still have all the power that iptables afforded. Continue reading “An Introduction to Firewalld”

Set Up a Default Webserver and Limit Access

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Pre-Flight Check
  • These instructions are intended to address specifically the following scenario: Set Up a Default Configuration Webserver and Limit Access
  • I’ll be working from a Liquid Web Self Managed CentOS 6.5 server, and I’ll be logged in as root.

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How To Unblock an IP Address in APF

Reading Time: < 1 minuteAdvanced Policy Firewall, or APF, is a software firewall commonly installed on Liquid Web servers. It is an interface to iptables, which is standard software for managing network ports on Linux. Interacting with iptables can be complex, but APF greatly simplifies the process. APF is only accessible via ssh, and there is no way to make changes in APF through WHM or cPanel.

Pre-Flight Check
  • These instructions are intended specifically for unblocking an IP Address in APF.
  • I’ll be working from a Liquid Web Core Managed CentOS 6.5 server, and I’ll be logged in as root.
  • For further details, see our in-depth look at the APF firewall.
Check APF for Your IP Address

Let’s say that you want to check whether or not a specific IP address, maybe 8.8.8.8 , is blocked by APF. That’s easy!

grep 8.8.8.8 /etc/apf/*

You may receive a result similar to:

/etc/apf/deny_hosts.rules:# added 8.8.8.8 on 04/25/14 13:42:01 with comment: {bfd.courier}
/etc/apf/deny_hosts.rules:8.8.8.8

The above means that BFD detected a brute force attack from the IP 8.8.8.8 on port 25, and automatically added a rule to APF to prevent future connections specifically from that IP address.

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