Linux System Engineer / Sysadmin Homelab builder Exploring cloud, monitoring, storage, networking, automation — and whatever else I find interesting along the way.
Linux Skill - Session tmux/screen
If you manage remote Linux servers over SSH, dropping your connection means losing your work — running processes, unsaved edits, and your entire terminal state. Terminal multiplexers like tmux and screen solve this by decoupling your session from the connection itself. Even if your SSH link dies, your session lives on the server, ready to be reattached. What Is a Terminal Multiplexer? A terminal multiplexer runs as a persistent server process on your remote machine. Your terminal becomes a client that attaches to this server — not the direct SSH shell itself. ...
SSL/TLS Part 3: Real-World Incidents, Renewal Horror Stories, and Lessons Learned
A Real-World Scenario Imagine this backend setup: nginx → backend API → database The nginx server and database are both fine. But an internal certificate on the backend API connection expired overnight. Now: Users can load the homepage But login fails Payment processing fails File uploads fail Users think: app bug, database issue, server overload. Developers check nginx: fine. Database: reachable. Error logs: x509: certificate has expired. Total downtime for something that could have been caught with a simple expiry alert, weeks in advance. ...
SSL/TLS Part 2: Certificates, Formats, and Why There Are So Many
What Is a Certificate? A TLS certificate is a digital identity card for a server. It answers the question: Is this really the server it claims to be? The certificate is issued and signed by a Certificate Authority (CA) — a trusted third party that has verified the server’s identity. When your browser connects to a website, it checks the certificate against a list of trusted CAs it already knows about. ...
SSL/TLS Part 1: The Security Protocol Behind HTTPS
SSL/TLS is a security protocol used to encrypt network traffic. SSL stands for: Secure Sockets Layer TLS stands for: Transport Layer Security Most people only notice SSL/TLS because of a small padlock icon in a browser, or the letters https:// at the start of a URL. But TLS is one of the most important technologies keeping the modern internet alive. Without it, passwords travel across networks in plain text. Banking becomes dangerous. APIs become unsafe. Cloud systems lose the ability to trust each other. ...
DNS Part 3: Recursive Resolvers vs Authoritative Servers
Why Some DNS Use Names And Some Use IPs Sometimes DNS servers use names: mike.ns.cloudflare.com sara.ns.cloudflare.com Sometimes they use IP addresses: 1.1.1.1 8.8.8.8 At first they look similar, but actually they are different types of DNS systems. Recursive DNS Resolver Examples: 1.1.1.1 8.8.8.8 These are public DNS resolvers. You configure them on: laptop router phone Their job is to find answers for you. Why Recursive DNS Uses IP Addresses Because your device needs DNS before it can resolve names. ...
DNS Part 2: Registrars, Providers, and Nameservers
Why So Many DNS Servers Exist? When you bought your domain from GoDaddy, GoDaddy was handling your DNS by default. Then when you moved to Cloudflare, Cloudflare asked you to change your nameservers. Example: Before: ns1.domaincontrol.com ns2.domaincontrol.com After: mike.ns.cloudflare.com sara.ns.cloudflare.com At first this feels weird: "Why need another DNS server? Isn’t DNS already working?" Registrar vs DNS Provider This is the important part many people misunderstand. Domain Registrar A registrar is where you BUY the domain. ...