Introduction Firewalld is a dynamic firewall management tool that is included in CentOS 7. It replaces the previous iptables service as the default firewall tool for CentOS 7. Firewalld is designed to make it easier to manage firewall rules and provide more flexibility in defining policies and rulesets. The primary purpose of Firewalld on CentOS 7 is to protect your system from unauthorized access by blocking inbound traffic that does not match specific rules or policies. It also allows you to define different network zones with different levels of security based on the level of trust you have ... Read More

Introduction NetworkManager is a daemon that manages the network connections on Red Hat Enterprise Linux (RHEL) and its community-based counterpart, CentOS. It handles both wired and wireless connections, including ethernet, WiFi, mobile broadband, VPNs, and other network interfaces. The daemon provides a graphical user interface for managing network settings on desktop environments such as GNOME or KDE. NetworkManager is designed to automatically detect and configure connections based on the available network devices and their properties. It uses a variety of mechanisms to connect to networks dynamically, including DHCP (Dynamic Host Configuration Protocol), PPP (Point-to-Point Protocol), static IP addresses, etc. Additionally, ... Read More

In today's digital age, internet connectivity plays a crucial role in our day-to-day lives. In order to connect to the internet, we need an address that identifies us on the network. This is where IP addresses come into play. IPv4 (Internet Protocol version 4) is the fourth version of IP addresses and has been used for many years. However, as technology advances and more devices connect to the internet, the number of available IPv4 addresses is running out. That's why IPv6 was introduced. Explanation of What IPv6 Is and Why Someone May Want to Disable It IPv6 (Internet Protocol version ... Read More

Introduction When you configure a router, one of the most important things you need to do is define its identity by setting a unique router ID. A router ID is an IPv4 address that identifies each router on a network. It is used to establish neighbor relationships between routers and determine the shortest path for data to be forwarded between network segments. Understanding What a Router ID Is To configure your router's identity correctly, it's essential to understand what a router ID is. Simply put, a router ID serves as an identifier for each device in ... Read More

In today's modern world, the utilization of the Internet is essential for many businesses and individuals alike. The Internet Protocol (IP) is a fundamental communication protocol that is used to connect devices over the internet. Internet Protocol Version 6 (IPv6) was introduced in 1998 as an improvement over IPv4 and has since become more widely adopted. Explanation of what IPv6 is and why someone may want to disable it IPv6 provides several advantages over its predecessor, including a larger address space, improved security, and better network performance. However, there are situations where disabling IPv6 may be necessary. For example, some ... Read More

Introduction Status codes are an integral part of web development. Whenever a user requests a webpage, the server responds with a status code to indicate the success or failure of the request. One such status code is 400 − Bad Request. It is essential for developers and webmasters to have a clear understanding of this error code as it can negatively impact user experience and SEO rankings. Overview of HTTP Status Codes HTTP status codes are a vital part of the internet, providing feedback to users and developers on the status of web pages ... Read More

Introduction When it comes to system security, it is essential to restrict root access as much as possible, especially when multiple users have access to the system. One of the ways a user can gain root access is by invoking the “su” command. While the su command allows a user to switch from one user account to another, it can be misused or abused by users with sudo privileges. In this article, we will explain what “su” access for sudo users means, why it's important to disable "su" access for sudo users and how you can do this. ... Read More

Introduction In today's interconnected world, network connectivity is critical for businesses and organizations of all sizes. However, connecting to the internet exposes your network to a number of security threats, including hacking attempts, malware infections, and data breaches. One essential tool in protecting your network from these threats is Static Network Address Translation (NAT). In this article, we'll take a closer look at what Static NAT is and why it's important for the Cisco Adaptive Security Appliance (ASA). Static NAT is a technique used to map an internal IP address to an external IP address ... Read More

Pandas, an influential Python library renowned for its data manipulation and analysis capabilities, offers an array of tools to empower data scientists and analysts alike. Among its key data structures, the DataFrame stands tall−a two−dimensional labeled data structure with columns of potentially diverse types. When traversing the vast landscape of DataFrames, it frequently becomes necessary to extract specific columns or a range of columns, an art commonly referred to as column−slicing. In this article, we embark on a journey to explore various methods that unveil the secrets of taking column−slices in Pandas. Brace yourself for an expedition through the following ... Read More

Introduction Linux is an open-source operating system that is widely used by developers, system administrators, and individuals who prefer a non-proprietary operating system. A Linux distribution, often simply called a "distro, " is a customized version of the Linux operating system that includes different software packages and configurations to fit specific needs. There are hundreds of Linux distributions available, ranging from popular ones like Ubuntu and Fedora to specialized ones like Kali Linux for cybersecurity professionals. Planning Your Distribution Identifying your goals and target audience Before starting, it is essential to identify your goals and target audience. What do you ... Read More