Osvaldo de Sousa

I stumbled across something genuinely useful while setting up a local NTP server for my home network: Starlink quietly added a GPS-based NTP server to every dish, accessible locally at a fixed IP address. It’s been there since mid-2024, it’s officially documented, and almost nobody is using it. Here’s what that means, why it matters, and how I put it to work. What Is NTP and Why Should You Care Network Time Protocol (NTP) is how computers agree on what time it is. This sounds trivial until you realise how many things depend on accurate time — TLS certificate validation, log correlation, authentication tokens, scheduled tasks, database transactions. When clocks drift, things break in subtle and maddening ways. ...

There’s a point every IT professional reaches where the home network becomes an embarrassment. You spend your days designing resilient, segmented, secure infrastructure for clients or employers, then you come home to a single flat network where your smart bulbs live alongside your workstation, your NAS, and your Hi-Fi system. Everything on the same broadcast domain. No segmentation. No visibility. Just trust and hope. That was my situation. This is the story of how I fixed it. ...

This is the beginning of osousa.com — my personal space to write about cybersecurity, networking, and whatever I happen to be learning or working on. I’m a Cybersecurity Analyst based in Mozambique, currently working at Hidroeléctrica de Cahora Bassa. After 20 years in IT across systems analysis, networking, and service desk management, I’ve recently moved fully into security — and there’s always something new to learn, document, and share. What to expect here Writeups on security topics, tools, and techniques Notes from training and certifications Observations from working in security within critical infrastructure The occasional post on networking, Linux, or systems No ads, no tracking, no fluff. Just notes from the field.