Ping the Networker

Sixteen levels cover the work a junior networker actually does: Firewall rules, top to bottom, with an implicit deny Spanning tree, including a port that stays blocking on purpose Port security and a sticky MAC Hop count and TTL A tunnel whose MSS is too big DNS records that point at the wrong address Subnet masks and a route that never matches DHCP snooping, a trusted port, and a helper address A fibre cut and the routes around it An out-of-band management network, separate from production Open the map to see every link, including the management cables. From the NOC, SSH into a device you have already unlocked. Help is in the app if a ticket stalls; using it marks the run as assisted. The game is free. It has no account, no ads, and no network connection. Scores and unlocked levels stay on this device.