Ragnar Review: Pi Network Scanner for Security Auditing

Your Raspberry Pi has been sitting in a drawer. Ragnar gives it a second life as an autonomous network security tool that scans WiFi, hunts vulnerabilities, and even wardrives — all from a headless box with a tiny e-Paper screen.

Now, Ragnar is an open-source fork of the Bjorn project by PierreGode, built for the Pi Zero 2W, Pi 4, and Pi 5 as well as headless Debian servers. Plus, it combines network scanning, vulnerability assessment, WiFi analysis, and wardriving into one self-contained package. The project sits at 759 stars on GitHub and is MIT-licensed.

What Ragnar’s Pi Network Scanner Actually Does

We installed Ragnar on a Pi Zero 2W with a Waveshare 2.13-inch e-Paper HAT and ran it through its paces. Still, the feature list is surprisingly broad for a tool that installs with a single curl pipe.

So how does the install go? Straightforward enough. One wget command, one sudo bash, and about 25 minutes later — depending on your Pi model and internet speed — you get a rebooted system with a web dashboard at port 8000.

Took us roughly 20 minutes on a Pi Zero 2W with a 100Mbps connection. The installer auto-detects your hardware profile and skips resource-intensive tools on lower-end models — a smart touch.

Ragnar’s Standout Features: WiFi Analysis & Wardriving

But the WiFi spectrum analyzer is the feature that surprised us most. It’s a passive, tri-band (2.4/5/6 GHz) RF troubleshooter in the web UI that shows every BSS with RSSI, channel width, security type, and AP-advertised channel utilization. Then it flags co-channel and adjacent-channel interference with color-coded recommendations for channels 1, 6, and 11. And it builds a walk-around coverage heatmap with adjustable floor size — from a 10m² room to a 300m² office. No aircrack-ng dependency — it uses plain iw scan passive under the hood. (For a more GUI-focused network analysis alternative, check out our Sniffnet quick review.)

Even the wardriving module impressed us too. It logs WiFi networks, BLE devices, and cell towers with GPS coordinates, exports to WiGLE CSV and KML formats. What makes it clever is the GPS interpolation: when you drive through a tunnel or lose GPS signal, it backfills missing positions from the breadcrumb track using speed-aware constant-acceleration math. Most wardriving tools just discard observations without GPS.

Then there’s the 802.11 WIDS (Wireless Intrusion Detection System) that listens passively for deauth floods, beacon floods, rogue APs, and KARMA/MANA attacks. It never transmits a frame — pure passive monitoring.

Ragnar’s Limitations: Hardware & Maturity

Though Ragnar is still in active development (the repo says “Status: Development”). Some features are beta-quality. Plus, the web interface is functional but not polished — expect occasional rough edges.

Hardware requirements add up. While the core scanning works on any Pi, the WiFi analysis and WIDS features need a monitor-mode adapter like the Alfa AWUS036AXM (around $40-50 on Amazon). The advanced vulnerability assessment tools (Nuclei, SQLMap, ZAP) require 8GB+ RAM and a Pi 4 or 5.

Also, it’s not a set-it-and-forget-it tool. The installer does a lot, but you’ll need basic Linux familiarity to troubleshoot display drivers, monitor-mode interfaces, or the occasional broken dependency. (If you’re setting up a Pi for security work, our WireGuard setup guide covers a compatible Pi configuration workflow.) The community behind it is small — just one main contributor and a handful of forkers.

Bottom Line: Is Ragnar Worth Your Pi?

Ragnar turns a spare Raspberry Pi into a capable network security toolkit that covers scanning, WiFi analysis, wardriving, and intrusion detection — all for the price of the hardware and a single install command. It’s not ready for production security audits, but for hobbyists, network enthusiasts, and anyone curious about wardriving or WiFi forensics, it’s one of the most practical Pi security projects we’ve tested this year.

Get it at github.com/PierreGode/Ragnar.