In this tutorial, you will learn how to set up a secure and functional email server on Ubuntu. From network preparation to installing Postfix (MTA), Dovecot (MDA), and the SnappyMail web client, without needing a database.
Email Server & Webmail Setup: Postfix, Dovecot, SnappyMail Read More »
Complete and practical guide on how to create a virtual machine and install Ubuntu 26 LTS Server on VirtualBox. Ideal for home labs, developers, and IT students.
Install Ubuntu Server 26 on VirtualBox (Step-by-Step) Read More »
Practical guide on how to configure NAT Overload (PAT) in Cisco Packet Tracer. See the network topology, essential router commands, and copy a complete script for your networking lab.
How to Configure NAT in Packet Tracer (Step-by-Step) Read More »
Protect your Linux servers against rootkits. Discover how to configure Zabbix to act as a File Integrity Monitor (FIM) and get real-time alerts if critical system files are unexpectedly altered.
Zabbix FIM: How to Setup File Integrity Monitoring Read More »
Learn step-by-step how to configure DHCP in Cisco Packet Tracer. See how to distribute IP addresses, masks, and gateways automatically using a dedicated server or a Cisco router.
Configure DHCP in Packet Tracer: Server & Router Guide Read More »
Discover why a cheap SSD can be a costly mistake. Learn the differences between SLC, MLC, TLC, and QLC cells, the risks of DRAM-less drives, and how to check your drive’s lifespan (TBW) before it fails.
Cheap SSDs: The Hidden Dangers of TLC, QLC & DRAM-less Read More »
If you manage a Zabbix environment, you’ve probably been there: a crowded “Problems” screen, where it’s hard to distinguish a critical production server from a forgotten test machine. In the past, we relied exclusively on Hostgroups to try to organize this mess. But in modern versions of Zabbix, there is a much more powerful and
Zabbix Tags Guide: Organizing and Filtering Monitoring Alerts Read More »
Let’s talk about one of the most primitive and, at the same time, most robust routing techniques: Flooding. Imagine you need to spread urgent gossip. You don’t choose a specific person; you shout to everyone nearby, and those people shout to the next ones, and so on. That is Flooding. 1. How does it work
Flooding Routing Algorithm: How It Works & Use Cases Read More »
If you have ever used a GPS to avoid traffic, you already intuitively understand the fundamental problem of computer networks. When you send a message, it needs to traverse a “web” of routers to reach its destination. But how do these devices decide where to go? Do they choose the path with the fewest cables?
Routing & Dijkstra’s Algorithm: Finding the Internet’s Shortest Path Read More »
Do you need your virtual machines (VMs) in VirtualBox to communicate with each other in isolation from your network and also isolated from the Internet? The “Internal Network” mode is the ideal solution for this scenario. Using VirtualBox in Internal Network mode is quite different from other network configuration forms in VirtualBox. For example, the
VirtualBox Internal Network: Setup & Isolation Guide Read More »
