Pinoy IT Share

Collision Domain vs Broadcast Domain: VLANs, DHCP, and Real-World Network Troubleshooting What happens when a network has multiple DHCP servers, improperly configured VLANs, and access points that were never moved to the new VLAN? Networking concepts such as collision domains , broadcast domains , VLANs , and DHCP can sound intimidating when first encountered. In theory, they are relatively straightforward. In a real network, however, these concepts can become the difference between a network that works reliably and one that suddenly causes users to lose access to critical systems. This article explains these concepts in a practical and beginner-friendly way while still keeping the technical details useful for network administrators and IT professionals. I'll also share a recent real-world lesson involving two DHCP servers operating within the same network , as well as a VLAN implementation issue where existing access points were not properly included in the new VLAN design. What ...

Whether you need to monitor critical edge routers, track bandwidth utilization, or receive instant notifications when a core switch drops offline, deep infrastructure visibility is non-negotiable. Zabbix 7.0 LTS remains one of the most powerful, flexible, and enterprise-grade open-source network monitoring solutions available today. This comprehensive guide breaks down the core architecture of Zabbix, walks through a containerized deployment using Docker Compose, demystifies SNMP polling and security considerations, provides a step-by-step walkthrough for onboarding network hosts, and shows you how to build real-time visual topology maps. 1. What is Zabbix? (Core Concepts) At its core, Zabbix acts as an automated, around-the-clock infrastructure watchdog. Continuous Health Checks: Zabbix systematically polls connected assets—including routers, managed switches, hypervisors, servers, and storage devices—for key health metrics such as uptime, CPU load, memo...

In software engineering, technical communication often falls into one of two extremes: either it is overly dense with jargon that alienates business stakeholders, or it is oversimplified to the point of losing its technical substance. However, elite engineering and product leadership rely on a rare skill: the ability to articulate complex system mechanics through intuitive, real-world analogs without sacrificing architectural precision. At the center of this communication challenge lies CRUD (Create, Read, Update, Delete)—the universal design pattern that governs data persistence across all software systems. This guide explores how to conceptualize CRUD with absolute clarity while leveraging it as a framework for technical authority. Part 1: The Intuitive Baseline (The Universal Mental Model) To explain CRUD to a non-technical stakeholder, product manager, or client without triggering cognitive fatigue, bypass the database terminology entir...

🏎️ The Analogy: 4WD vs. AWD (How Traffic Flows) 🧠 What Exactly is dnsdist? (The "Brain" of the Operation) Most of us are already familiar with DNS resolvers like AdGuard Home, Pi-hole, or BIND. They are responsible for translating website names (like google.com ) into IP addresses. But what is dnsdist ? Simply put, it is not a DNS server. It is a DNS-, DoS-, and abuse-aware load balancer . Using the store analogy: If your DNS servers are the Cashiers , dnsdist is the Store Manager and Security Guard standing right at the entrance of your shop. It doesn't have its own cash register, but it decides exactly where the customers should go. Here are the three main things it does for your network: 🔀 Smart Traffic Routing (Load Balancing): It doesn't just blindly pass traffic along. It evaluates which DNS server is available, responding quickly, and not overloaded before handing over the query. ⚡ Instant Caching: dnsdist has its own memory. If five devices in your ho...

Separation of Concerns in IaC: Why We Pair YAML Templates with JSON Parameters When designing scalable Infrastructure as Code (IaC), one of the earliest architectural hurdles engineers face is configuration sprawl. Hardcoding values directly into infrastructure templates quickly leads to code duplication and maintenance nightmares. To solve this, a widely adopted industry best practice is the Separation of Concerns (SoC) : utilizing YAML for the core infrastructure blueprint and JSON for the environment-specific parameters. Here is a technical breakdown and practical guide on why this specific combination serves as an ideal design pattern for modern DevOps pipelines. Why the Split? (YAML vs. JSON) YAML for Main Templates: Highly readable and human-centric. It uses indentation instead of noisy brackets, making complex, multi-resource architectures easy to audit. It also natively supports inline comments ( # ) for documenting architectural decisions. JSON for Param...

Summary Legacy USB multi-function peripherals are notoriously unreliable in modern multi-device households. Proprietary vendor software is often bloated, platform-dependent, and prone to "Printer Offline" errors. This case study details the engineering of a Network-Native Print & Scan Gateway using Proxmox VE, CUPS, and eSCL. 1. Why Virtualize? The Homelab Paradigm Deploying this within a Proxmox homelab environment offers critical engineering advantages: Hardware Abstraction: The print server is encapsulated in an LXC container, decoupling it from physical hardware. Snapshot Resilience: We utilize Proxmox snapshots as "undo points" for configuration changes. Resource Isolation: Negligible resource consumption (50-100MB RAM) in an isolated sandbox. 2. Network Topology [ Windows Clients ] [ macOS / Mobile ] │ │ └────────────┬───────────┘ ...

Automating OpenCanary Honeypot Integration with MikroTik In the modern cybersecurity landscape, relying solely on static firewall rules to drop packets is a failing strategy. Automated botnets and malicious actors constantly probe network perimeters. To truly secure an infrastructure—whether it is a complex enterprise environment or an advanced homelab—we need a system that actively fights back. Today, we are building an automated "Active Defense" pipeline that turns reconnaissance attempts into instant hardware-level bans. Network Security Topology - Honeypot to MikroTik Router Automation Flow 1. Core Concepts: The Deep Dive Before deploying code, it is critical to understand the architecture and why we select specific tools to make this setup completely "idiot-proof." The Honeypot (Decoy Concept): A honeypot is an intentionally vulnerable system placed on your network. It serves no legitimate business purpose. Therefore...