Pinoy IT Share

Understanding Custom Chains Ever wondered what makes MikroTik firewalls so flexible? It’s the custom chain feature — a powerful way to group and reuse firewall rules efficiently. Think of it as creating “mini rule blocks” or “functions” inside your firewall configuration. Let’s break it down in a practical, Pinoy-friendly way. 🔥 What Is a Custom Chain? In MikroTik, a custom chain works like a shortcut or function . Instead of writing repetitive rules for every scenario, you can group related ones together. When a packet matches your condition, you “jump” into your custom chain, process the rules, then return to the main flow. ⚙️ Example: LAN Traffic Filtering Here’s a simple setup where we handle LAN traffic separately: # MikroTik Firewall Example /ip firewall filter add chain=forward src-address=192.168.88.0/24 action=jump jump-target=LAN-RULES add chain=LAN-RULES protocol=tcp dst-port=80,443 action=accept comment=...

DNS for Beginners: Simple Guide to How the Internet Works The Domain Name System (DNS) is like the phonebook of the internet. It translates human-friendly domain names like pinoytechshare.blogspot.com into IP addresses that computers understand. In this guide, we'll break down DNS in simple terms for beginners. 1. How DNS Works When you type a website address in your browser: Your device asks a resolver (usually your ISP) to find the IP address. The resolver checks its cache. If not found, it queries the root DNS servers . Root servers point to TLD servers (like .com, .org). TLD servers point to the authoritative server for the domain. The resolver gets the IP and your browser connects to the website. 2. Common DNS Record Types A record: Maps a domain to an IPv4 address. AAAA record: Maps a domain to an IPv6 address. CNAME: Alias of another domain. MX: Mail exchange server for email delivery. NS: Nameserver for the domain. TXT: Text...

Understanding CGNAT (Carrier-Grade NAT / NAT444) Continuing from our discussion on why you shouldn’t use public IPs in DHCP networks , let’s dive deeper into what Internet Service Providers (ISPs) do when they run out of public IPv4 addresses. The answer lies in a system called Carrier-Grade NAT (CGNAT) — also known as NAT444 . 🌐 Why CGNAT Exists The Internet runs primarily on IPv4, which uses 32-bit addresses — a maximum of about 4.3 billion unique IPs. When the internet started, that number seemed huge. But as the number of devices, mobile users, and ISPs exploded, the available IPv4 pool began to dry up. ISPs faced a dilemma: assign each customer a unique public IP and eventually run out, or find a way to share a smaller number of IPs among thousands of users. That’s where CGNAT comes in. CGNAT allows multiple subscribers to share a single publi...

RCA Hindi Lang Para sa Incidents: Ang Lihim na Lakas ng Root Cause Analysis Usually, ginagamit lang natin ang Root Cause Analysis (RCA) kapag may nangyaring mali — tulad ng machine breakdown, project delay, o customer complaint. Pero kung iisipin mo, parang nag-aalaga ka lang ng kalusugan kapag may sakit ka na. 😅 Ang totoo, RCA ay hindi lang pang-incident report — ito ay disiplina ng pag-aaral at continuous improvement. Para kang general sa gera — hindi lang niya inaalala kung paano siya nanalo, pinag-aaralan din niya kung bakit siya natalo . Ano nga ba ang RCA? (Simplehan Natin) Think of RCA as detective work para sa business mo 🕵️‍♀️. Hindi lang ito tungkol sa “anong nangyari,” kundi “ bakit ito nangyari?” Kapag nahanap mo ang ugat, sure ka na hindi na ito mauulit. 1. Identify the problem. 2. Collect clues. 3. Ask “Why?” over and over. 4. Find the real cause. 5. Fix and verify. Bakit Dapat Gamitin ang RCA Kahit Walang Incident Imagine mo kung...

RCA Is Not Only for Incidents: The Hidden Power of Root Cause Analysis Introduction – RCA Isn’t Just for When Things Go Wrong Most people think RCA (Root Cause Analysis) is something you only use after a disaster — like when a machine breaks, a project fails, or a customer gets angry. But that’s like visiting the doctor only after you collapse. RCA is more than a fix-it tool — it’s a smart way to learn, prevent, and improve before problems explode. Think like a general: Great generals study how wars were lost to avoid repeating mistakes. Smart businesses use RCA to study defeat patterns — not to blame, but to build stronger strategies. What Exactly Is RCA? (Explained Simply) Think of RCA like detective work for your business. 🕵️‍♀️ Instead of just fixing a symptom, you dig deeper and ask “ Why? ” over and over until you find the real reason behind a problem. How RCA Works (Simple Steps) Spot the problem: What went wron...

My Proxmox Journey: From Zero to an Enterprise-Like Setup How a beginner can build a real, production-style homelab using Proxmox — step by step and one service at a time. Everything Runs on Proxmox (Except the Router) Almost everything in my homelab runs inside Proxmox VE , my main virtualization platform. Only my bare-metal Mikrotik router sits outside it — the router handles the network edge, internet routing, VLANs, DHCP, and firewall rules. Proxmox acts like a mini data center at home — it lets me run VMs (virtual machines) and LXCs (lightweight containers). I use LXCs for lightweight services and VMs for workloads that need more isolation or resources. What’s Inside My Proxmox Host Type Tool Function LXC Zabbix Server Monitors my network and systems LXC rsyslog Collects and centralizes logs LXC n8n Automatio...