Ragnar: A Pocket-Sized Network Security Lab

How a $20 Raspberry Pi Zero 2 W and a tiny e-ink screen became a serious network testing tool.

June 2026 • by PierreGode (open source project)

There's something satisfying about a security tool that fits in your shirt pocket. Ragnar — created by PierreGode and forked from the Bjorn project — is exactly that: an autonomous network scanner, vulnerability assessor, and offensive security toolkit that runs on a Raspberry Pi with a tiny 2.13-inch e-Paper display. It discovers hosts, finds open ports, checks for vulnerabilities, and reports results on that little ink screen in real time.

Think of it as a Tamagotchi for network administrators — except instead of feeding a digital pet, it's mapping your network's weaknesses while sitting quietly on a desk, drawing almost no power.

Important Ragnar is designed for educational and authorized testing purposes only. Only use it on networks you own or have explicit permission to test.

What Ragnar Actually Does

Ragnar isn't just a fancy nmap wrapper. It combines a broad set of capabilities that you'd normally need several separate tools to replicate:

Network Scanning Discovers live hosts and maps open ports across your network automatically.

Vulnerability Assessment Runs Nmap-based scans and, on beefier hardware, Nuclei (5,000+ templates), Nikto, SQLMap, and OWASP ZAP.

Threat Intelligence Fuses live data from CISA KEV, NVD CVE, AlienVault OTX, and MITRE ATT&CK in real time.

Wardriving Logs Wi-Fi networks, BLE devices, and cell towers with GPS positions. Exports to WiGLE CSV and KML.

Wi-Fi Isolation Testing AirSnitch checks whether a network properly isolates clients — useful for auditing guest Wi-Fi.

AI-Powered Analysis Optional GPT-5 Nano integration for vulnerability prioritisation and remediation advice.

Credential Testing Brute-force testing on FTP, SSH, SMB, RDP, Telnet, and SQL services.

E-Paper Display Real-time status showing targets found, vulnerabilities, credentials, and network info — no monitor needed.

Everything streams to a web dashboard accessible at http://<ragnar-ip>:8000, which includes a file manager, system monitor, hardware auto-detection, and a mobile-friendly Wi-Fi configuration portal.

The Hardware Build

The classic Ragnar build is deliberately minimal — and deliberately cheap. The whole point is a self-contained device you can leave running on a network without it being conspicuous or expensive to replace.

Raspberry Pi Zero 2 W ~$15–20 including shipping — don't pay more

Waveshare 2.13" e-Paper HAT waveshare.com

MicroSD card (16GB+) Class 10 recommended

USB power supply (5V/2A) Standard micro-USB

Pi Zero 2 W Pricing Warning A Pi Zero 2 W should cost you no more than around $20 shipped. Some resellers massively inflate prices. Check the official Raspberry Pi website or authorised distributors. If you're seeing $50+ listings, walk away.

Ragnar also runs headless (no display) on standard Debian or Ubuntu servers (AMD64, ARM64, ARMv7), and there's even a port for the WiFi Pineapple Pager with its full-colour LCD screen.

Supported Platforms

Platform	Notes
Raspberry Pi Zero 2 W / Pi 4 / Pi 5	64-bit Pi OS (Debian Trixie, kernel 6.6+). Set username and hostname to `ragnar`. The Pi Zero 2 W automatically skips resource-heavy tools to stay lean.
Debian / Ubuntu Server (headless)	Debian 11+ or Ubuntu 20.04+. AMD64, ARM64, or ARMv7. Minimum 2GB RAM, 2 CPU cores, 10GB disk. Systems with 8GB+ RAM get advanced scanning tools automatically.
WiFi Pineapple Pager	Firmware 1.0.7+, PAGERCTL payload installed. Full-colour LCD display with button navigation and LED indicators.

Installing Ragnar

Installation is a single-script affair. Flash a fresh 64-bit Raspberry Pi OS image, set the hostname and username to ragnar, then:

wget https://raw.githubusercontent.com/PierreGode/Ragnar/main/install_ragnar.sh
sudo chmod +x install_ragnar.sh && sudo ./install_ragnar.sh

The installer detects your hardware automatically — Pi with e-Paper, headless server, or Pineapple Pager — and configures the right profile. It handles package installation, Python dependencies, ARM optimisations (using PiWheels on ARM hardware), and on 8GB+ RAM machines it installs the full advanced security toolkit automatically. Expect it to take a while; it pulls in a lot. Reboot when it finishes.

Full step-by-step instructions are in the official Install Guide on GitHub.

The Web Interface

Once running, everything is accessible via the web UI at http://<ragnar-ip>:8000. You get real-time network discovery results, the threat intelligence dashboard, a file manager with image gallery, system monitoring, and hardware profile information. If Ragnar can't reach a known Wi-Fi network, it creates a Ragnar hotspot (password: ragnarconnect) and you configure credentials via http://192.168.4.1:8000.

Advanced Mode: 8GB+ RAM

On a proper server with 8GB or more of RAM, Ragnar unlocks a significantly more powerful set of tools — real-time packet capture with tcpdump and tshark, deep protocol inspection (HTTP, DNS, SMB, SSH), automated anomaly detection, OWASP ZAP with authenticated scanning support (eight auth types including OAuth2, Bearer Token, and Cookie-based), Nuclei with over 5,000 templates from ProjectDiscovery, Nikto, SQLMap, and CVE correlation against NVD and CISA KEV feeds.

If you have an existing install and want to add these, just run:

cd /home/ragnar/Ragnar
sudo ./scripts/install_advanced_tools.sh
sudo systemctl restart ragnar

Bonus: Ragnar + Pwnagotchi

One of the more fun touches is a built-in bridge to Pwnagotchi. You can swap between Ragnar and Pwnagotchi modes via the web UI or with a physical PiSugar 3 button — double-tap or long press switches between them, with a 10-second cooldown to prevent accidental triggers. If you're building a multi-purpose security Pi, this is a neat way to get two tools in one device.

Where to Get It

Everything is open source under the MIT licence. The project has over 500 GitHub stars and is actively maintained.

→ Ragnar on GitHub
→ Full Install Guide
→ PierreGode's GitHub Profile
→ Waveshare 2.13" e-Paper HAT

Tip Set a static IP for your Ragnar device on your router. It makes life much easier, especially if you're switching between Ragnar and Pwnagotchi modes and the Wi-Fi adapter briefly reconnects with a different DHCP address.