Ubuntu 24.04 Firewall: A Quick Guide

Understanding and managing the firewall on your Ubuntu 24.04 system is crucial for ensuring the security and efficiency of your network. A firewall acts as a gatekeeper, controlling inbound and outbound traffic based on predetermined security rules. Ubuntu 24.04 comes equipped with ‘ufw’ (Uncomplicated Firewall), a user-friendly interface for managing iptables, the default firewall tool on Linux. Whether you’re a seasoned system administrator or a curious user, this guide will walk you through the essentials of using the ufw firewall, including installation, configuration, testing, and more.

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How to show/check for open ports on Ubuntu Linux

How to show/check for open ports on Ubuntu Linux

Checking for open ports on Ubuntu Linux is an essential part of security administration. Some Linux software works by listening for incoming connections. A simple example would be a web server, which handles user requests on HTTP port 80 or HTTPS port 443 whenever someone navigates to a website. As a Linux administrator or user, it’s important to always know which ports of your system are open to the internet. Otherwise, you could be unaware of outside connections being made to your computer, which consumes bandwidth and resources, along with being a potential security vulnerability.

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How to enable/disable firewall on Ubuntu 20.04 LTS Focal Fossa

How to enable/disable firewall on Ubuntu 20.04 LTS Focal Fossa Linux

The default Ubuntu firewall is ufw, which is an acronym for “uncomplicated firewall.” It comes automatically installed on all editions of Ubuntu Desktop and Ubuntu Server. Ufw is a frontend for the typical Linux iptables commands, but it is developed in such a way that basic firewall tasks can be performed without the knowledge of iptables. You may find you need to disable ufw if it is blocking some necessary connections, or you can enable it for increased security.

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How to bind a rootless container to a privileged port on Linux

One of the main innovations introduced by Podman was the ability to run rootless containers. Security wise, this was a big improvement, since a potentially compromised container running as root represents a security threat for the host system. In order to obtain a similar behavior, recent versions of Docker support running the docker daemon in the user context. Running unprivileged containers, albeit more secure, has also its drawbacks, as the inability to bind to privileged host ports.

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How to enable/disable firewall on Raspberry Pi

How to enable/disable firewall on Raspberry Pi

The firewall on a Raspberry Pi will, by default, block incoming connections to certain ports. This is a security feature, but may cause problems if you try to configure an SSH server on your Raspberry Pi, host a website, or otherwise host some service that needs to accept incoming connections. The usual answer to this problem is to configure the firewall to accept the connections on the particular ports that you need to open. Another alternative is to disable the firewall completely.

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Best firewall for Linux

Best firewall for Linux

A firewall is a line of defense on your network, primarily used to filter incoming traffic, but also used for outbound rules and other network related security. All major Linux distros come with a software firewall built into them, since it is part of the Linux kernel itself. Any user can configure their system firewall to get started with securing network traffic, but there are many alternatives to the default which will extend or simplify the functionality.

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How to define a custom Firewalld zone

Firewalld is the default high-level firewall manager on the Red Hat family of distributions. One of its peculiarities is that it defines a series of so called firewall zones: each zone can be considered like a different level of trust and can be configured to allow traffic through a specific set of ports. While Firewalld comes with some predefined zones which can be easily examined and modified, sometimes we may want to create our custom zones from scratch.

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