5 Best Practices to Prevent SSH Brute-Force Login Attacks in Linux

Introduction

Typically, SSH-enabled servers make for easy targets for brute-force attacks. The ongoing development further increases the risk of intrusion by hackers of new software tools and bots for automating brute-force attacks.

This manual will look at strategies to protect your SSH servers from brute-force attacks on Linux distributions based on RHEL and Debian derivatives.

1. Disable SSH Password Authentication and Enable SSH-Key Authentication

Username/password authentication is the standard authentication technique for SSH. But as we have seen, brute-force attacks can be used to target password authentication systems. Implementing key-based SSH authentication, in which authentication is made possible via public and private SSH key pairs, is advised to be safe. While the public key is copied to the server, the client’s private key stays on their computer.

During SSH key authentication, the server verifies whether the client PC has the private key. A shell session is created, or the command supplied to the remote server is executed if the check is successful. You may find detailed instructions for configuring SSH key-based authentication on our website. (more…)

How to Analyze and Optimize MySQL performance

Introduction

MySQL is an open-source relational database that many users prefer to use in their daily operations because of the diversity of storage engines it supports, its flexibility and high performance, robust data security, cost-effectiveness, ease of maintenance, and reliability.

Why should MySQL performance be measured and monitored?

Ensuring smooth and effective database performance is one of the most important features of any organization or company, large or small. Thus, in some cases, having a complete understanding of database uptime or load is crucial and should be monitored frequently.

As a result, numerous monitoring tools are available on the market to track, analyze, and measure performance, as well as examine potential difficulties. They help you optimize queries and visualize database metrics, collect statistics, and present the performance status so that you can understand the influence on overall performance and potential issues that need to be troubleshot.
The following advantages may emerge from optimizing database performance: (more…)

Setup Secure FTP server on Linux using VSFTPD

Introduction

Have you ever worked away from home and realized that you left a critical document on your computer? The optimal method is to utilize an FTP server such as Very Secure FTP Daemon (VSFTPD).
You can install and configure an FTP server using VSFTPD on your Linux server by following the steps in this guide. With this server, you can safely transfer files to other computers.

Continue reading, and you’ll never have to worry about your files being held hostage on your home computer again!
The File Transfer Protocol, sometimes known as FTP, is a standard network protocol that sends and receives data to and from remote networks. Linux users have access to various open-source FTP servers to choose from. PureFTPd, ProFTPD, and vsftpd are the ones that have the most notoriety and are utilized the most frequently. We will install vsftpd (Very Secure FTP Daemon), a dependable, secure, and quick FTP server. In addition, we will demonstrate how to configure the server so that users can only access their home directories and the entire transmission is encrypted using SSL/TLS.

Although FTP is a highly used protocol, you should consider using SCP or SFTP instead if you want to transfer data in a more protected and expedient manner.
In this blog, we will use Ubuntu and similar Debian base distribution; however, any other Linux distribution should also work. (more…)

How to install and use Cacti on Ubuntu 20.04

What is Cacti

The following features are offered by Cacti, a comprehensive network graphing solution created to maximize the potential of RRDtool’s data storage and graphing functionality:

  • Remote and local data collectors
  • gadget discovery
  • generation of devices and graphs automatically
  • Device and graph tagging
  • individual data gathering techniques
  • Controls over the user, group, and domain access

All of this is contained inside a simple interface that is both intuitive and easy to use and is appropriate for both small LAN installations and extensive networks with hundreds of connected devices.

Ian Berry created it as a high school project in the early 2000s. Hundreds of businesses and enthusiasts have used it to monitor and manage their enterprise networks and data centers.

Suppose you see any issues referencing missing tables or columns in the database, whether you are working with the source code or downloading the code directly from the repository. In that case, you must perform the database upgrade script. (more…)

Top Linux GPU monitoring and Diagnostic Tools

Introduction

The components shown on a computer monitor are controlled by a specialized circuit board known as a video card. It is also known as a graphics processing unit or GPU and is responsible for calculating 3D visuals and pictures for use in Linux gaming and other applications. Let’s have a look at the best Linux command-line tools for GPU monitoring and diagnostics so we can fix this problem.
There is a possibility that a graphical processing unit (GPU), often called a video or graphics card, could be present on a Linux machine. Active graphics card monitoring and control can be necessary for various contexts, including mining cryptocurrencies, operating gaming servers, or improving the user experience on a desktop computer.

GPU monitoring and Diagnostic Tools

lshw -C display -short

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Using Windows ipconfig Command

Introduction

The ipconfig command updates DHCP and DNS settings and displays details about your network configuration. The ipconfig command by default shows the default gateway, subnet mask, and IP address. However, you may extract much more information from it with the right parameters.
The ipconfig command and its various options will be explained in this article.

How to Open Command Prompt

You must open the Command Prompt window in order to use this tool. The Command Prompt window can be opened in one of three ways:

  1. Use the Windows search feature to look for “cmd.”
  2. Right-click the Start button and choose Command Prompt.
  3. Press WinKey + R on your keyboard, and then type cmd in the Run window.

How to use the ipconfig command

So, let us start with something easy, like how to use the ipconfig command.
After CMD is opened. Type:

ipconfig

This will show you the most basic information about your network from your network adapters.

ipconfig command

As you can see from the above screenshot, the Command will tell you about each network adapter on your computer. In this case, we have a wired (ethernet) network adapter and a wireless (Wi-Fi) network adapter. If you have a VPN client, it will also show up as a network adapter.

all Option

The Command displays only the most basic network information without using any parameters. But by default, no information on the DNS and DHCP servers is shown. You must use the /all argument to display all the details about your network adapter.

ipconfig /all

The following details will be returned for each network adapter in your device:

ipconfig options

ipconfig output

The ipconfig /all tool is frequently used to diagnose issues with network connections.

release Option

The ipconfig command can reset or update your network settings and display information about your configuration. You can ask the DHCP server for a new IP address if DHCP is enabled on your network card.
To start, the current IP address must be made public. Doing this will let the DHCP server know that we no longer want to use the provided IP Address.

ipconfig /release

ipconfig release

The Command will, by default, release the IP addresses for every network interface. Additionally, a single network adapter may be specified. It would help if you input the name of the adapter that you see here in the output of ipconfig in order to accomplish this:

ipconfig /release Wireless*

ipconfig wireless

renew Option

After releasing an IP Address, a new one must be requested from the DHCP server. This is possible using the Ipconfig /renew Command:

ipconfig /renew

If the renewal was successful, you would receive the same output as the ipconfig command, which includes an overview of your new IP Address, subnet mask, and gateway.
Once more, we can specify a single network adapter by providing the adapter’s name.

ipconfig /renew Wireless*

Display DNS Command

Your computer maintains a local cache of all visited DNS records. This cache quickly translates domain names to their corresponding IP addresses. This eliminates the need for your computer to contact the DNS server each time you visit Google.com, for example:
You can perform the command ipconfig /displaydns to view the DNS cache’s contents.
This will display each DNS record in the DNS cache:

ipconfig /displaydns

ipconfig display dns

Flush DNS Command

Occasionally, your DNS Cache may contain obsolete records, resulting in DNS-related errors (unable to reach websites, for example). Typically, this can be resolved by executing the flush DNS Command.

ipconfig /flushdns

The ipconfig /flushdns command clears your DNS Cache. This is risk-free; your computer will simply request updated DNS records from the DNS servers.

How to install and use ncdu on Linux

What Is Ncdu?

The name “NCurses Disk Usage” (or “Ncdu”) refers to a curses-based alternative to the well-known “du” command. It offers a quick method of determining which directories are taking up disk space.

The creator of the Ncdu software is not happy with all of the tools and methods available in Linux for analyzing disk utilization. Therefore, he used the C programming language and a ncurses interface to create Ncdu.

Ncdu is a straightforward and quick disk utilization analyzer used to determine which directories or files on local or distant computers are using up more space.

Without further ado, let’s get started learning how to install Ncdu in Linux and how to use it to check disk utilization in Unix-like operating systems like Linux.

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How to install Wireshark on Windows Server and use it

Introduction

This blog will teach you how Wireshark functions. We’ll walk you through where to find and install the Wireshark application on your PC or Server. You will learn how to start a packet capture and what data you may expect to receive from it. The Wireshark lecture will also show you how to utilize the data manipulation features in the interface fully. You’ll also learn how to get data analysis tools better than Wireshark’s built-in features.

What can you do with Wireshark?

As one of the most dependable network protocol analyzers on the market in recent years, Wireshark has gained a solid reputation. This open-source program has been used as a comprehensive network analysis tool by users worldwide. Users can use Wireshark to analyze network security vulnerabilities, debug protocols, and learn about network activities.

How to Use Wireshark

Wireshark is a network protocol analysis tool, as was already described. Wireshark’s primary function is to deconstruct data packets sent across various networks. The user can look for particular data packets and filter them, then examine their passage across their network. These packets can be examined either in real-time or offline.

The user can use this data to produce statistics and graphs. Originally known as Ethereal, Wireshark has become one of the most important network analysis tools. Users who want to view data from various networks and protocols should use this tool.

Both novice and professional users can utilize Wireshark. Once you understand how to capture packets, the user interface is easy to use. Advanced users can decrypt packets using the platform’s decryption capabilities as well.

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Using fdisk to manage Partitions

Introduction

One of the most time-consuming tasks while using Linux is managing partitions. If you are unfamiliar with the operating System, you could initially find the procedure complicated.

But it’s crucial to understand how to handle partitions on your computer since disk partitioning is necessary for many processes, including installing an operating system and file organization.

Here is a tutorial on creating, resizing, and removing partitions on Linux using the Fdisk program.

What is fdisk?

Fdisk is a text-based command-line tool for Linux that allows you to inspect and manage hard disk partitions. You can use the disk space to install operating systems, back up your data, and manage your files by using it to support a variety of partition tables and create, delete, and alter disk partitions.

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How to use ifconfig in Linux

Introduction

To configure, manage, and query network interface parameters through the command-line interface or in a system configuration script, use the “interface configuration” (abbreviated as “ifconfig”) program on Unix/Linux operating systems.
The “ifconfig” command can display the current network configuration information, configure a network interface’s hardware address, IP address, netmask, or broadcast address, create an alias for the network interface, and enable or deactivate network interfaces.
The “Useful “ifconfig” Commands” and their real-world applications are covered in this article. They could be very useful to you when managing and configuring network interfaces in Linux systems.

View All Network Interface Settings

Without any parameters, the “ifconfig” program will list all the details of the current interfaces. The assigned IP address of a server can also be checked using the ifconfig command.

ifconfig

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