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Configuring a Slave DNS Server with BIND9

In this guide, you will learn how to configure a slave DNS server using BIND9 on Debian. This server will sync with the master server (dns1.javiercruces.org) and distribute the name resolution load in your local network. You will also be guided to verify that the zone transfer works correctly. In this case, the slave server is located in the 192.168.10.0/24 network, with the IP 192.168.10.200. 1. Initial Setup of the Slave Server Hostname First, assign the correct hostname. Edit the /etc/hostname file:

Saturday, May 10, 2025 | 5 minutes Read
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Installation and Configuration of BIND9 on Linux

In this guide, you will learn how to install and configure a DNS server on Linux using BIND9. You will set up forward and reverse lookup zones for your domain, allow DNS queries from other machines on the network, and perform tests using tools like dig. You will also learn how to configure forwarders to efficiently resolve external domain names. 1. Initial Preparation Create the DNS Machine Create a machine and set its name to dns1.yourname.org.

Sunday, May 4, 2025 | 3 minutes Read
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Installing Prometheus with docker-compose and Node Exporter on Debian 12

This guide is an introductory tutorial that shows how to install, configure, and use a basic instance of Prometheus using Docker Compose. Additionally, a Linux machine (in this case Debian 12) will be configured to expose its system metrics, which will be collected by Prometheus using Node Exporter. Prerequisites Docker and Docker Compose installed A Linux machine with administrator privileges Creating files Creating the docker-compose All the files used in this post can be found in my github.

Thursday, April 17, 2025 | 3 minutes Read
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Installing Docker Compose on Ubuntu 24

Complete guide to installing and managing Docker Compose on Linux systems. Installation from Repository For Debian/Ubuntu-based Systems sudo apt-get update sudo apt-get install docker-compose-plugin For RHEL/CentOS-based Systems sudo yum check-update sudo yum install docker-compose-plugin For Fedora-based Systems sudo dnf update sudo dnf install docker-compose-plugin Updating the Plugin Update on Ubuntu/Debian sudo apt-get update && sudo apt-get upgrade docker-compose-plugin Update on RHEL/CentOS sudo yum update docker-compose-plugin Manual Installation Direct Download of the Binary DOCKER_CONFIG=${DOCKER_CONFIG:-$HOME/.docker} mkdir -p $DOCKER_CONFIG/cli-plugins curl -SL https://github.com/docker/compose/releases/download/v2.25.0/docker-compose-linux-$(uname -m) -o $DOCKER_CONFIG/cli-plugins/docker-compose chmod +x $DOCKER_CONFIG/cli-plugins/docker-compose Global Installation (for all users) sudo curl -SL https://github.com/docker/compose/releases/download/v2.25.0/docker-compose-linux-$(uname -m) -o /usr/local/lib/docker/cli-plugins/docker-compose sudo chmod +x /usr/local/lib/docker/cli-plugins/docker-compose

Sunday, March 9, 2025 | 1 minute Read
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Installing Docker on Ubuntu 24

To start using Docker Engine on Ubuntu, make sure you meet the prerequisites and follow the installation steps. Prerequisites Operating System Requirements To install Docker Engine, you need the 64-bit version of one of these Ubuntu releases: Ubuntu Oracular 24.10 Ubuntu Noble 24.04 (LTS) Ubuntu Jammy 22.04 (LTS) Ubuntu Focal 20.04 (LTS) Docker Engine for Ubuntu is compatible with x86_64 (or amd64), armhf, arm64, s390x, and ppc64le (ppc64el) architectures. Note: Installation on Ubuntu-derived distributions, such as Linux Mint, is not officially supported (although it may work).

Sunday, March 9, 2025 | 7 minutes Read
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Installation GNS3 in Debian 12

In this article, I present an update of the process of installing GNS3 in Debian 12, based on the previous post for Debian 11. If you need more detailed details about the installation or configuration of GNS3, I recommend you review the previous version. GNS3 installation We update the repositories and install the available system updates. javiercruces@HPOMEN15:~$ sudo apt update -y && sudo apt upgrade -y We install the necessary dependencies for GNS3, including Python, virtualization tools (KVM, QEMU, libvirt), additional libraries (PyQt5, dynamipes) and other utilities.

Sunday, September 8, 2024 | 3 minutes Read
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How to Choose Which GPU to Use on My Laptop with Linux

If you have a Linux laptop with an NVIDIA GPU, you may have noticed that the video ports are not working properly after installing the graphics drivers. If this sounds familiar, don’t worry—I’ve got you covered. I’ve been investigating and found a tool that can save you several headaches. It’s called EnvyControl, a command-line utility (CLI) that allows you to easily choose which graphics card you want to use on your computer. This is especially useful if your laptop has a hybrid graphics configuration, such as Intel + NVIDIA or AMD + NVIDIA.

Sunday, September 1, 2024 | 3 minutes Read
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Installation and Configuration of MariaDB in Debian 12

MariaDB installation and configuration in Debian 12 To install MariaDB in Debian 12, follow these steps: 1.Update the repositories and install the MariaDB package: First, update your system repositories and install MariaDB: javiercruces@jcruces:~$ sudo apt update javiercruces@jcruces:~$ sudo apt install mariadb-server 2.Enable and start the MariaDB service: Once installed, set MariaDB to automatically start the start and then start the service: javiercruces@jcruces:~$ sudo systemctl start mariadb javiercruces@jcruces:~$ sudo systemctl enable mariadb 3.Configure MariaDB:

Sunday, September 1, 2024 | 2 minutes Read
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Installation of NVIDIA Controllers in Debian 12

The installation of NVIDIA drivers in the Linux universe has traditionally been a challenge, especially in distributions such as Debian, where free software policies often complicate the process. In this post I will explain a simple way to install NVIDIA drivers using the official Debian repositories. In addition, at the end of the article, you will learn to install a key tool called Nvidia Optimus, which will provide you with the ability to select which graphics card you will use.

Sunday, September 1, 2024 | 5 minutes Read
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Interconnection of database servers

This post addresses how to configure and manage connections between different databases, both homogeneous and heterogeneous, to facilitate interoperability between various database systems. Throughout the article, different connection scenarios are explored, starting with configurations between databases of the same type, such as Oracle to Oracle or PostgreSQL to PostgreSQL, and then moving towards heterogeneous connections between different technologies, such as Oracle to MySQL, PostgreSQL to Oracle, and vice versa. It also covers the steps needed to configure links, create users, and modify key configuration files, allowing remote consultations.

Sunday, September 1, 2024 | 9 minutes Read
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Oracle installation 19c under Debian 12

Installing Oracle 19c on Debian 12 may seem complicated, but don’t worry, I’m here to guide you in every step. In this post, I will explain to you in a simple way how to prepare your system and make the installation of Oracle 19c in Debian 12. Update the repositories The first thing is to update the repositories of our virtual machine and in case we don’t have any packages we update it:

Sunday, September 1, 2024 | 4 minutes Read
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PostgreSQL installation in Debian 12

In this post, I will guide you through the process of installing PostgreSQL in Debian 12, creating a user with basic permissions, and how to create and consult a database. #1. PostgreSQL installation To install PostgreSQL in Debian 12, follow these steps: Update the repositories and install PostgreSQL * *: First, make sure your system is updated and install PostgreSQL: ```bash sudo apt update sudo apt install postgresql ``` Verifies that the service is in operation * *: After installation, make sure that the PostgreSQL service is in operation:

Sunday, September 1, 2024 | 3 minutes Read