Viewing the iptables rules configured on our Linux system

Collection of basic Linux Firewall iptables rules

The purpose of this guide is to show some of the most common iptables commands for Linux systems. iptables is the firewall built into all Linux distributions. Even distros like Ubuntu, which utilizes ufw (uncomplicated firewall), and Red Hat, which utilizes firewalld still pass their commands to iptables and use it in the background.

Mastering iptables, or at least becoming familiar with some of the most basic commands, is essential for Linux administrators. Even casual Linux users can benefit from understanding the basics of the iptables firewall, since they may be required to apply some minor configurations to it at some point. Use some of the examples below to familiarize yourself with the iptables syntax and get an idea for how it works to protect your system.

WARNING
You should not apply iptables rules to a production system until you are somewhat familiar with how they work. Also be careful when applying rules to remote systems (a computer that you have established an SSH session with) because you can accidentally lock yourself out if you enter the wrong rule.

In this tutorial you will learn:

  • Collection of basic Linux firewall iptables rules
Viewing the iptables rules configured on our Linux system

Viewing the iptables rules configured on our Linux system

Read more

Developing and running an Android app on a Linux system

Get Started with Android application development using Linux and Android SDK

Developers interested in the Android mobile operating system are able to use the Android SDK and various IDE software to code applications. These apps can then be made available and marketed to Android users around the world.

There are a lot of choices when it comes to programming Android applications. Your coding environment can involve a Linux system and a variety of different IDE programs to facilitate all of the software development. The trouble here is that each Linux distribution will often have a different set of requirements to run the sofware, and a separate list of steps that need to be followed.

In this guide, we’ll go through the step by step instructions to install Android Studio – which is one of the most popular Android IDEs – on a Linux system. This will work on any distribution because we’ll be using Snap package manager to manage the installation. Love it or hate it, the Snap package manager gets your system ready for Android development very quickly, by handling all the dependencies and working identically on any distribution you’re running, whether it be Ubuntu, Debian, Red Hat, CentOS, AlmaLinux, openSUSE, or any other type of Linux system.

Follow along with us below as we setup Snap package manager, install Android Studio, and then program a Hello World Android application to verify that everything is working properly.

In this tutorial you will learn:

  • How to setup Snap package manager
  • How to install Android Studio and SDK packages
  • How to create a Hello World test application
  • How to run an Android application on an emulated device

Read more

Configuring SSH login without password between two systems

SSH login without password

If you ever get tired of typing in your SSH password, we’ve got good news. It’s possible to configure public key authentication on Linux systems, which allows you to connect to a server through SSH, without using a password.

The best part is, using key authentication is actually more secure than typing in a password each time. This is in addition to being far more convenient. It also allows you to automate certain tasks, such as rsync scripts or other Bash scripts that utilize SSH, SCP, etc.

The process for setting up key authentication involves generating RSA keys on one system, then copying the key to a remote host. This works on any Linux distribution and is a short and easy process. Follow along with the instructions below as we take you through the step by step guide to configure passwordless SSH on Linux.

In this tutorial you will learn:

  • Generate RSA keys and transfer to remote system
  • How to login with SSH without a password

Read more

Mounting an NTFS partition on a Linux system

How to mount partition with ntfs file system and read write access

NTFS stands for New Technology File System and is created by Microsoft for use on their Windows operating systems. It doesn’t see much use on Linux systems, but has been the default file system on Windows for many years. Linux users are probably used to seeing drives with the ext4 file system, which is normally the default and definitely the most widespread in the Linux world.

Although NTFS is a proprietary file system meant especially for Windows, Linux systems still have the ability to mount partitions and disks that have been formatted as NTFS. Thus a Linux user could read and write files to the partition as easily as they could with a more Linux-oriented file system. This can be particularly handy in situations where you recover a disk from a Windows machine and wish to read the contents from your Linux system.

In this guide, we’ll show command line examples of how to mount NTFS partitions on any Linux distribution. This will include examples for mounting with only read access, or read and write access, as well as temporary mounting or persistent mounts that will survive future reboots. Read on to learn how.

In this tutorial you will learn:

  • How to install ntfs-3g and fuse on all major Linux distros
  • How to mount NTFS formatted partition on Linux
  • How to persistently mount NTFS partition
  • How to mount NTFS partition with read only and read and write access

Read more

How to configure, mount, and access encrypted partition on Linux

How to encrypt partition in Linux

One of the best ways to protect your files on a Linux system is to enable hard disk encryption. It’s possible to encrypt an entire hard drive or partition, which will keep every file that resides there safe. Without the correct decryption key, prying eyes will only be able to see cryptic gibberish when they try to read your files.

In this guide, we’ll go over the step by step instructions of using LUKS to encrypt a Linux partition. Regardless of what Linux distro you’re running, these steps should work the same. Follow along with us below to get partition encryption configured on your own system.

In this tutorial you will learn:

  • How to install cryptsetup on major Linux distros
  • How to create an encrypted partition
  • How to mount or unmount encrypted partition
  • How to setup disk encryption during Linux install
How to configure, mount, and access encrypted partition on Linux

How to configure, mount, and access encrypted partition on Linux

Read more

Creating an SSH tunnel through port forwarding on Linux

Enable SSH port forwarding on Linux

Most Linux users are familiar with the SSH protocol as it allows remote management of any Linux system. It’s also commonly used for SFTP to download or upload files. SSH is known as a very secure protocol because it encrypts traffic end to end. But the encrypted tunnels it creates are actually quite versatile and can be used for more than just remote server management or file transfer.

SSH port forwarding can be used to encrypt the traffic between two systems for pretty much any protocol. This is accomplished by creating a secure tunnel and then routing another protocol’s traffic through that tunnel. By principle, it works very similarly to a VPN.

In this guide, we’ll go over the step by step instructions to show you how to use SSH port forwarding to create a secure tunnel for some other application. As an example, we’ll create port forwarding for the telnet protocol, which is usually avoided because of how it transfers data in clear text. This will secure the protocol and make it safe to use.

In this tutorial you will learn:

  • How to use SSH port forwarding
  • How to create a persistent SSH tunnel

Read more

Using aria2 to download a file on Linux

aria2 – all in one command line download tool

aria2 is a command line tool for Linux systems that can download files using a variety of protocols, including HTTP/HTTPS, FTP, SFTP, BitTorrent and Metalink. It’s diverse download capabilities make it an all-in-one tool for downloading files on Linux.

Most users know about downloading files from the command line by using wget or curl. aria2 has a few advantages over both tools, because it has increased potential for greater download speed by downloading from more than one source in the single session. aria2 can also pause and resume downloads.

In this guide, we’ll show you how to install aria2 on major Linux distros, then give you some command line examples so you see how to download various file types with the program. By the end of this guide, you’ll know how to use aria2 to download files through various protocols, and pause or resume downloads.

In this tutorial you will learn:

  • How to install aria2 on major Linux distros
  • aria2 command line usage examples
  • How to download a file from multiple mirrors
  • How to pause or resume downloads in aria2

Read more

Using mdadm to create a software RAID 1 array on Linux

Linux Software Raid 1 Setup

RAID 1 is a hard disk configuration where the contents from one hard disk are mirrored onto another. This provides the user with some redundancy in case a disk fails. On your Linux system, the two hard drives are represented as a single file system. But in the background, making changes to your files is actually writing the changes to two disks at the same time. You can also add more than two disks to the configuration, as long as you keep the number even. Otherwise, something like RAID 5 will be more suitable.

There are many ways to configure a RAID setup. One of the easiest and most accessible ways is through the mdadm software package, which can be installed and used on any major Linux distribution. This is easier than some other RAID setups, since it doesn’t require any special hardware (like a RAID controller) and isn’t that hard to configure.

In this guide, we’ll go through the step by step instructions to install and setup mdadm on Linux, and create a RAID 1 configuration for two hard disks. Our example scenario will consist of two empty hard disks that are each 10 GB in size. This is in addition to our main hard disk, which is just used for the operating system.

WARNING
Strictly speaking, RAID 1 is not a proper backup solution. It does provide some protection from disk failure, but what if you accidentally delete a file or a virus corrupts multiple files? Those undesirable changes are instantly written to both disks. RAID 1 provides high availability, but you shouldn’t use it as your only backup solution.

In this tutorial you will learn:

  • How to install mdadm on major Linux distros
  • How to partition hard disks for RAID setup
  • How to create a new RAID device in mdadm and mount it
  • How to keep the RAID array mount persistent
Using mdadm to create a software RAID 1 array on Linux

Using mdadm to create a software RAID 1 array on Linux

Read more

Installing Concrete5 CMS on Fedora Linux

Installation of Concrete5 CMS on Fedora Linux

Concrete5 is a CMS (content management system) which allows users to edit any page via editing toolbar and change its content or design without reading complicated manuals or navigating a complex administration back-end.

In this article, we’ll go over the step by step to install Concrete5 CMS on Fedora Linux. This will include setting up Apache as an HTTP server, various PHP modules, and MariaDB to host the database.

In this tutorial you will learn:

  • How to install prerequisite packages for Concrete5 CMS
  • How to setup a MariaDB database and user for Concrete5
  • How to install and configure Concrete5 CMS

Read more

Recover – Reset Forgotten Linux Root Password

The root account, sometimes called super user, is the admin account on a Linux system, and is essential for performing all kinds of administrative tasks. You’ll need access to it in order to install or remove packages, manage other user accounts, and a lot more things. Anytime you access the root account, either through the su or sudo commands, you’ll be prompted for the root password.

If you have forgotten the password to your system’s root account, you don’t necessarily have to go back to square one and reinstall the whole operating system. It’s possible to recover and reset the root password, even without the old password. In this guide, we’ll take you through the step by step instructions of recovering a forgotten root password on Linux. This will work regardless of the Linux distribution you’re running, as long as its using the GRUB bootloader. Other bootloaders will have similar instructions.

In this tutorial you will learn:

  • How to reset a forgotten root password on Linux

Read more