I've been building Network Doctor, a terminal tool for figuring out why a connection isn't working. One of the features that got a little out of hand is Challenge Mode. It drops you into a simulated broken network, gives you the symptoms, and asks you to diagnose what is actually wrong. The same diagnostic engine that Network Doctor normally uses is available to you, but the idea is to see whether you can interpret the evidence correctly. The scenarios include things like DNS failures, blocked ports, routing problems, connection refusals, dual-stack IPv4/IPv6 issues, and other network faults. You make your diagnosis, submit it, and the simulator knows the actual fault so it can score the answer. I originally built the simulator for testing Network Doctor itself. At some point I realized it was basically generating networking troubleshooting puzzles, so I made them playable. It's written in Go and runs entirely in the terminal. GitHub: https://github.com/heymaikol/network-doctor Simulator Documentation: https://heymaikol.github.io/network-doctor/wiki/Simulator-Overview/ Challenge Mode Documentation: https://heymaikol.github.io/network-doctor/wiki/Challenge-Mode/ I'd love ideas for network failures that would make particularly nasty troubleshooting challenges.   submitted by   /u/mplaczek99 [link]   [comments]