Debian Security

This bundle of guides shows how to securely connect to a Debian compute instance and how to harden it from attacks using public SSH keys, firewalls, AV software, and other tools.
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How to Use nftables

nftablesreplaces the successful iptablesand its related frameworks built on Netfilter. With nftables come improvements to performance and usability, but also significant changes to syntax and usage.

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How to Secure MySQL Server

MySQL MySQL is an open-source relational database management system. This guide will show you how to secure and audit a MySQL server.

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Cloud Firewall

Linode’s Cloud Firewall is a robust cloud-based firewall solution available at no additional charge for Linode customers.

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Anti-Virus Protection with ClamAV and rkhunter

Anti-virus and Rootkit Detection This guide teaches you how to use ClamAV, ClamTK, and rkhunter for anti-virus and rootkit detection to secure your server.

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How to Install SELinux on Debian 10

Ubuntu has a Mandatory Access Control (MAC) system similar to SELinux, named AppArmor. Both SELinux and AppArmor provide a set of tools to isolate applications from each other to protect the host system from being compromised.

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How to Configure a Firewall with UFW

What is UFW? UFW, or uncomplicated firewall, is a frontend for managing firewall rules in Arch Linux, Debian, or Ubuntu.

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How to Use Fail2ban to Secure Your Server (A Tutorial)

What is Fail2Ban Fail2ban is a log-parsing application that monitors system logs for symptoms of an automated attack on your Linode.

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How to Set Up and Secure a Linode Compute Instance

After you have successfully created a Compute Instance, there are a few initial configuration steps you should perform within your new Linux system.

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How to Use SSH Public Key Authentication

Public key authenticationwith SSH (Secure Shell) is a method in which you generate and store on your computer a pair of cryptographic keys and then configure your server to recognize and accept your keys.

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Controlling Network Traffic with iptables - A Tutorial

iptables is an application that allows users to configure specific rules that will be enforced by the kernel’s netfilter framework.

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Modify File Permissions with chmod

Modify File Permissions with chmod The chmod command allows users to change read and write permissions in Unix systems.

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Linux Users and Groups

If you are new to Linux/Unix, then the concept of permissions may be confusing. This guide provides you with an explanation of what permissions are, how they work, and how to manage them.