Endless randomized subnetting practice for CCNA & Network+, using the magic-number method. Fully offline — no ads, no accounts, no tracking.
Questions, bugs, or feature requests — email me anytime and I'll get back to you.
hello@tylerdix.comIs Subnet Driller free?
Yes — completely free. No ads, no accounts, and no in-app purchases.
Does it need an internet connection?
No. Everything runs on your device. Questions are generated and graded locally — nothing is pulled from a question bank or generated by an AI model.
What does it drill?
Randomized subnetting questions using the magic-number method: network address, first and last usable host, broadcast address, and usable host counts — in both multiple-choice and written-answer formats. Every miss shows the full breakdown.
Which devices are supported?
iPhone and iPad, running a current version of iOS / iPadOS.
How do I reset my stats?
On the practice screen, tap the SESSION or TOTAL chip and confirm. That clears the matching stats; nothing leaves your device either way.
Effective date: May 23, 2026
Subnet Driller collects nothing. The app runs entirely on your device with no network connection, no account, and no third parties.
None. Subnet Driller does not collect, store, or transmit any personal information.
If you turn on the optional daily reminder, it is scheduled as a local notification on your device. No data leaves the device, and deleting the app removes everything.
Subnet Driller is rated 4+ and collects no personal information from anyone, including children.
If this policy changes, the updated version will be posted here with a new effective date.
Questions about this policy? Email hello@tylerdix.com.