Guides, deep dives and daily notes on the things that actually break: networks, servers, DNS records, tokens, and the tooling around them. Every piece is written to answer the question first, then show the working.
Browse by topic: Security, Network, Dev, Sysadmin, SEO and Email & DNS. Or reach for a tool when you need the answer computed rather than explained.
NetworkHow to do a DNS lookup from the command lineYou push a DNS change, then sit there wondering if it actually took. Don't wonder, ask: nslookup example.com works on any OS, Windows included,…18 June 2026
NetworkHow to show your IP address from the command lineSomeone on the phone asks for your IP, and you blank on which command your OS wants. Windows takes ipconfig; Linux wants ip addr,…18 June 2026
SysadminHow to change file permissions with chmodSo the script won't run, or a web folder throws a 403 you can't explain. That's permissions, and the fix is usually chmod 644…18 June 2026
DevGLM-5.2 vs GPT-5.5 and Opus 4.8: benchmarks and priceMid-June, every AI feed we follow was yelling the same headline: the cheap open model just beat GPT-5.5. Mostly true. GLM-5.2, the open-weight model…17 June 2026
SEOWordPress vs a static site: which to run in 2026So you're starting a site, and everyone you ask has already picked a side. Here's the honest answer: it's a trade-off, and it hangs…16 June 2026
NetworkHow to change your DNS zone at OVHThe new server is up, the IP is sitting in your clipboard, and the OVH panel is doing its best to hide the one…16 June 2026
SysadminHow to manage services with systemctlThe service is down, you've got a shell, and the fix is one systemctl verb away. systemctl status nginx tells you whether it's running…16 June 2026
SysadminHow to find files with find on LinuxA disk fills up, or a config file vanishes, and suddenly we need one file out of fifty thousand. find is the tool for…16 June 2026
DevHow to search text in files with grepSomewhere in this project sits the line that sets that value, and we have no idea which file. grep 'pattern' file searches one file,…16 June 2026
DevHow to download a file and test an API with curlSome CDN link just handed you a 200-byte HTML file instead of the zip. We've been there, and the fix is one letter: curl…16 June 2026
SysadminHow to extract and create tar.gz archives (tar)Someone hands us a release.tar.gz and the clock's already ticking. Two commands cover almost everything: tar -xzf archive.tar.gz unpacks one, tar -czf archive.tar.gz folder…16 June 2026
SecurityHow to generate an SSH key (ssh-keygen)Still typing a password every time you SSH into a box? One command ends that: ssh-keygen -t ed25519, then Enter to accept the default…16 June 2026
SysadminHow to kill the process using a port on LinuxYour server won't start and the terminal throws 'address already in use'. Something's squatting on that port, and sudo lsof -i :8080 (or ss…16 June 2026
SysadminHow to kill the process using a port on WindowsYour dev server won't start, and Windows greets you with 'address already in use'. Something's squatting on the port, and the fix is to…16 June 2026
NetworkHow to flush the DNS cache on LinuxYou fixed the DNS record, and your Linux box keeps serving the old IP anyway. On modern Ubuntu, Debian and Fedora the fix is…16 June 2026
NetworkHow to flush the DNS cache on WindowsA site moved servers yesterday and your PC keeps loading the old one. That's the Windows DNS cache holding a stale answer, and one…16 June 2026
NetworkHow to see a saved WiFi password on WindowsSomeone asks for the WiFi password and you realize you typed it once, two years ago, and it's gone from your head. Your PC…15 June 2026
NetworkWhat is DNS TTL? Cache, propagation and the values to useYou changed the record an hour ago, and half the office still lands on the old server. That's DNS TTL: the number of seconds…12 June 2026
NetworkWhat is a /24? CIDR notation and subnet masks, finally clearA ticket lands asking for a /24 for the new floor, and everyone in the thread nods like that obviously means something. Here's what…12 June 2026
SecurityTLS 1.2 vs TLS 1.3: what changed and what to run in 2026You upgrade nginx, point a checker at the host, and half your endpoints still answer TLS 1.2. Does that matter? Mostly no, and here's…12 June 2026
Email & DNSSPF, DKIM and DMARC explained: the records your email needsYour invoice email just landed in spam, and the content wasn't the problem. The DNS was. SPF, DKIM and DMARC are the three records…12 June 2026
SecurityHow long does it take to crack a password in 2026?Eight random characters. That's all that stands between a stolen database and your account, and a single modern GPU rig chews through it in…12 June 2026
SecurityAre JWTs encrypted? No, and the difference will bite youSomeone on your team pastes a production JWT into the group chat and half the room shrugs, because it's encrypted anyway, right? It isn't.…12 June 2026