Subnet Driller

Fast, offline subnetting practice for CCNA and Network+ candidates. Random questions, deterministic answers, built-in block size reference, and zero ads or accounts.

An offline subnetting quiz for CCNA, Network+, and other certification candidates - questions randomly generated, answers deterministic, every calculation hand-verified.

It drills the "magic number" / block-size method I memorized before my own exams: built for speed and repetition.

Features:

• Built-in block-size ("magic number") reference, one tap away
• Five randomly generated questions per session
• SESSION and TOTAL counters to track progress
• Fully offline - no accounts, ads, tracking, or subscriptions
• Built by a working network engineer with AI-assisted tooling, and thoroughly tested

About me: I'm a working network engineer and active CCNA, residing in Arizona, USA.

Questions, feedback, or bug reports? I read and reply to every email personally.