Author: Danilo

SSH Passwordless Authentication on RHEL 8 allows administrators to access remote systems without entering a user password on every connection. This method uses SSH key-based authentication, providing a secure and practical way to manage Linux servers remotely. SSH uses a client-server architecture to establish encrypted communication between systems. Instead of validating access through a password, key-based authentication relies on a pair of cryptographic keys generated on the client side and configured on the SSH server. In this guide, we will demonstrate how to create an SSH key pair, transfer the public key to a remote RHEL 8 server, and validate…

Resetting the root password on RHEL 8 shows a procedure to reset the root password. As a system administrator, it’s essential to store all the system’s passwords securely. However, what do you do if you lose the root password for a specific system? What do you do if you do not have a non-root user with sudo permissions? This is the worst situation, and you, as a system administrator, must be prepared to handle it. We will show a procedure to reset the root password by booting the system into the special mode. In this mode, the boot process stops…

Handling Target System State on RHEL 8 shows how to control the boot process of RHEL 8 and define the state you want your system to boot into. First and foremost: What is “systemd”? Serving as a system and service manager for Linux operating systems, the systemd software suite provides tools and services for controlling, reporting, and system initialization. Key features include: The basic object that systemd manages is a systemd unit, which represents system resources and services. A systemd unit consists of a name, type, and a configuration file that defines and manages a particular task. You can use unit files…

How to Install RHEL 8 on Lab shows all the necessary steps to install Red Hat Enterprise Linux 8 on a lab environment. Downloading the Installation File (.iso) First and foremost, access http://access.redhat.com/ and create an account if you have not yet: After accessing your account, go to Products –> under Downloads and Containers, click on Downloads: All available downloads will be shown, segmented by category. Click on “Red Hat Enterprise Linux”: For this lab, we’re using RHEL 8.10 – Feel free to use another version: Booting with Installation File We created a VM and set it up to boot…

VM Replication with vSphere Replication and Site Recovery Manager shows a possible scenario for using vSphere Replication and Site Recovery Manager (SRM) to replicate and manage virtual machines. Our scenario is based on a lab topology, as shown in the following picture: The “Main Site” is the active site, where all production virtual machines are hosted. The “DR Site” is the passive site and receives VM replicas from the active site. There are many technologies and configurations on this topology, but we will focus on vSphere Replication (VR) and Site Recovery Manager (SRM). What is vSphere Replication (VR)? VMware vSphere…

IPsec VPN on VyOS demonstrates how to establish a secure tunnel between two sites over the Internet. I have written some articles about VyOS. If you want to check the articles, you can read them by accessing the following links: I have started working on a new network topology, simulating a company with a Main site and replicating some virtual machines to a disaster recovery (DR) site. It is a complex scenario that involves numerous technologies and configurations. We can see the topology in the following picture: The primary goal is to establish a secure communication channel between the sites, utilizing…