Subnet Driller - CCNA Practice
Subnetting practice & quizzes
Free · Designed for iPad. Not verified for macOS.
An offline subnetting quiz for CCNA, Network+, and other certification candidates. Questions are randomly generated, answers are deterministic, and every calculation is 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 question types: network address, broadcast, first and last usable host, usable host count
- Multiple choice or written answers - or a mix of both
- SESSION and TOTAL counters, plus a per-type accuracy breakdown
- Optional daily practice reminder
- Fully offline - no accounts, ads, tracking, or subscriptions
- Shamelessly vibe coded using Fable 5; the subnet math lives in its own package and is hand-verified for accuracy
About me:
I'm a working network engineer and active CCNA, living in Arizona, USA.
Questions, feedback, or bug reports? I read and reply to every email personally.
Subnet Driller is an independent study tool, not affiliated with, endorsed by, or sponsored by Cisco Systems, Inc. or CompTIA, Inc. CCNA and Network+ are trademarks of their respective owners.
Fixed: if your device region uses a comma as the decimal separator — Norwegian, German, French, Portuguese and many others — you could not type an IP address at all, because the number pad has no period key. Commas now become dots as you type.
Regions that use non-Latin numerals (Arabic, Persian, Hindi) now work too.
Thank you to the person who wrote in about this — please keep the reports coming.
The developer, Tyler Dix, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
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Information
- Seller
- Tyler Dix
- Size
- 2.6 MB
- Category
- Education
- Compatibility
Requires iOS 18.0 or later.
- iPhone
Requires iOS 18.0 or later. - iPad
Requires iPadOS 18.0 or later. - Mac
Requires macOS 15.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 2.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2026 Tyler Dix