Break Linux. Break networks. Have fun.
(on purpose. then we fix it. usually.)
Every Linux pro started exactly where you are: staring at a blinking cursor, wondering what to type. These are fun, hands-on labs for curious people. No boring theory, no pressure, no exam. Grab any old computer, build something silly, break it, and find out why.
Start with LinuxI'm brand new👻 Try Linux right here- 28labs & hauntings to break
- $0forever free
- 1old computer needed
- ∞"wait, what?" moments
"The terminal doesn't care where you started. It only cares what you type next." so type something, and see what happens
🐧 Linux labs
Start at the top and work your way down, or jump to whatever makes you curious. Side effects may include late nights and saying "ohhh, so that's how it works" out loud.
Your first hour in the terminal
Stop being scared of the black screen. Move around, make things, and delete them like a pro.
The terminal isn't scary. It's just very, very honest.
Read the guide →Who's allowed to touch this file?
Owners, groups and those mysterious rwx letters, finally explained.
Linux has trust issues. Healthy ones.
Read the guide →Pipes: Linux's secret superpower
Chain tiny commands together and find out who's knocking on your server's door.
It's plumbing, but for data. No wrench required.
Read the guide →A service that refuses to die
Turn a script into a real Linux service that starts at boot and comes back when killed.
Like a zombie, but helpful. And it writes logs.
Read the guide →Build a wall (a friendly one)
Put a firewall on your server so only the doors you choose are open.
Nobody gets in without an invitation. Not even you, if you're careless.
Read the guide →Detective mode: why is it so slow?
Create a mystery on purpose, then track down the culprit with Linux's built-in tools.
Every slow server has a suspect. Today you're the detective.
Read the guide →Your computer works night shifts now
A bash backup script that runs by itself every night with cron.
It works the night shift so you can sleep.
Read the guide →SSH keys: never type a password again
Log in with a key instead of a password: faster, and much harder to break.
Passwords are so last decade.
Read the guide →Ghost Cam: catch a haunting on Grafana
Point a camera at your server, let a ghost loose, and prove what it did with graphs.
Ghosts hate graphs. Graphs have a memory.
Read the guide →The Linux+ Break Room: a haunted server
My Linux+ lab, turned into a game you can play. The server is haunted: files move, dead services rise again, doors open in the night. You're the ghost hunter, and every ghost turns out to be Linux. All 10 cases are live, from permissions to a full séance. Real Linux on real (or virtual) boxes, the way I learned it.
Enter the Break RoomCase 01Case 05Case 10: the séance👻 Possessed PC (real Linux, in your browser)🔨 Let's break Linux (and fix it)One line of magic
"My disk is full!" Every Linux user says it eventually. This one line finds the five biggest things in your home folder, using the same pipe trick from the pipes lab.
Paste it into any Linux terminal. Worst case, you learn something.
# who's eating my disk? du -sh ~/* ~/.[!.]* 2>/dev/null | sort -h | tail -5 # du = measure each folder # ~/.[!.]* = hidden ones too (hi, ~/.cache) # sort -h = order by size (1K, 2M, 3G...) # tail -5 = show the 5 biggest # the culprit is always Downloads. always.
🌐 Network & home lab projects
Once Linux feels like home, put it to work: block ads, build a VPN, run a tiny data center. Every guide has a sketch, the exact commands, and a way to break it.
Block ads for your whole house
Turn a Raspberry Pi into a DNS server that blocks ads and trackers for every device at home.
Warning: your smart TV is going to be very upset with you.
Read the guide →Reach home from anywhere
Build a private VPN so your phone can reach your home network from anywhere, without opening a port.
Your router keeps its doors locked. Your phone gets a secret tunnel.
Read the guide →Watch your network talk
Capture packets and watch a web page load one conversation at a time.
Like reading your computer's group chat. It's surprisingly chatty.
Read the guide →Build a virtual network
Routers and switches on your laptop, no hardware needed.
All the routers, none of the electricity bill.
Read the guide →Give an old laptop a second life
Turn an old laptop into your first home server.
From dusty drawer to data center. A very small data center.
Read the guide →A dashboard for your home
Watch your devices and internet, and get an alert on your phone when something goes down.
Because "is the internet down?" deserves a real answer.
Read the guide →Let Python do the boring bits
A small script that logs into your lab routers and backs up their configs.
Automate it once, never do it again. That's the dream.
Read the guide →Split your home network
Practise putting guests and smart gadgets on their own network in Packet Tracer, then see how it works at home.
Your smart plug doesn't need to see your laptop. Boundaries are healthy.
Read the guide →A mini data center on one PC
Build the spine-and-leaf design big data centers use, entirely in software.
A data center that fits in your laptop. We live in the future.
Read the guide →Meet your new lab buddies
You don't need shiny gear. The best home lab friends are the ones nobody else wants. Slow, loud, dusty? Perfect. They're not junk, they're lab buddies.
The laptop with the dead battery
Plugged in forever, lid cracked, still boots. Make it a 24/7 server. It will never leave you (it can't, it's on the charger).
The retired office PC
Offices sell them for pocket money every time they upgrade. Stuff it full of VMs and it purrs like a jet engine. Lovingly.
The Raspberry Pi in the drawer
Bought for "a project" three years ago. Today is its day. Pi-hole, a VPN, a tiny web page, anything.
The old router
Everyone has one in a cupboard. Flash it, VLAN it, turn it into the lab's grumpy gatekeeper.
🏠 My own crew
A Raspberry Pi that does way more than it signed up for, a pile of old laptops that refused to retire, and a couple of second-hand Dell and HP servers that sound like they're about to take off. None of them are new. All of them are family.
Rule of the lab: if it powers on, it's invited.
Never touched Linux before?
Perfect. That's the best place to start. Here's the whole plan.
Get a Linux box
WSL on Windows, a free VM, an old laptop or a Raspberry Pi. Whatever you have is enough.
Break something
Every lab ends with a "break it" challenge. That's where the real learning, and the fun, happens.
Hi, I'm Arun 👋
By day I'm an HPC Network Operations Engineer. By night, I'm the guy rescuing old computers nobody wants and giving them silly jobs. Home labs are my favourite hobby: the only hobby where breaking things counts as progress and a noisy fan counts as company.
Funny side effect: every cert I've earned started as me playing around in the lab (here they are). The studying was real, but the lab is what made it stick: I got curious, broke stuff, and the learning snuck in.
My current favourite toy? A CompTIA Linux+ lab I worked through. Somebody (me) breaks a Linux box on purpose, and somebody else (also me) has to figure out what went wrong. Best game ever, so I shared it: the Linux+ Break Room.
So this isn't a course and there's no exam at the end. It's just for fun. If one of these labs makes you grin, go "wait, what?", and try the next one, it's done its job.
Side effects of a hobby
These certs are what the hobby gave me. Each one added new skills and a lot more curiosity, and each has labs on this site that scratch the same itch.
A+
Opening up old PCs just to see what's inside. Most of them even went back together.
IT Support Professional
Where the terminal stopped being scary. Troubleshooting, a first taste of Linux, and learning to read the error message before panicking.
Network+
Subnets, DNS and the eternal "why can't this thing ping that thing?" Easier to learn when it's your own network misbehaving.
CIOS
The bonus round: CompTIA hands this one out when you hold A+ and Network+. Zero extra breaking required.
CCNA
VLANs, subnetting and routing only really clicked after I broke them on purpose in a virtual lab. Many times.
Linux+
Everything I broke on purpose, on a pile of old machines, then fixed. The whole story is one click away.
CSSS
Bonus round two: hold A+ and Linux+ and CompTIA hands you this one. Old PCs plus Linux is exactly how the hobby started.
CLNP
Bonus round three: Network+ and Linux+ together. Linux boxes talking to each other, which is what half my labs are about.
NCA-AIIO
Curiosity about what's actually inside giant AI data centers. Spoiler: lots of servers, lots of cables, lots of fans.
NCP-AIN
How huge clusters get wired together, spine-and-leaf style. The mini data center lab is its tiny, noisy cousin.
CCNA: passed (eventually) ✅
My first practice test went so badly I said, "I had been preparing for my funeral in the actual exam the whole month." So I stopped watching videos and started breaking things in the lab. The folks at PingMyNetwork kindly shared how I climbed out of that hole.
Read the whole story →The labs did the heavy lifting. Pick any one above, break something, and see where your curiosity takes you.
This website is haunted
Something is hiding in here. Five clues, one secret room. All you need is curiosity, and maybe a terminal.
clue 1 of 5
The first one is hidden in this page's source code. The part of a website nobody reads.
How do I see the source?
On a computer: right-click → View Page Source (or Ctrl+U). From a terminal: curl -s https://arunnetworkingpro.com | grep -i -A3 clue, where -s keeps curl quiet, -i ignores upper/lower case and -A3 shows 3 lines after each match.
Every clue teaches a real trick. The last one is always DNS.
Built something cool? Broke something spectacular?
Tell me about it, ask a question, or suggest the next lab. I read every email.
arun@arunnetworkingpro.comOr say hi on LinkedIn