Subnetting drill other environment
Randomized CIDR practice with difficulty tiers and a streak your browser remembers.
What 'other' means here
This tool lives in the green room because it GENERATES exercises (randomness) and REMEMBERS your streak (state) — two things the catalogue's fixed input-to-output tools do not do. The math it quizzes is the site's own CIDR engine.
Everything — the questions, the grading, the score — happens in your browser. Nothing is generated on or sent to a server.
Pick a difficulty and each round deals ten fresh questions drawn from a new random seed, so no two rounds repeat. The subnet arithmetic is computed by the same engine behind the CIDR tool, so every canonical answer is exactly what that tool would produce.
Your current streak, best streak, and lifetime score are kept in your browser's local storage and never leave it. Clear them any time with Reset; nothing here is uploaded or tracked.