Is the free tier actually free?

Yes. The Edge tier is free forever -- no credit card, no trial clock. You only pay if you choose to upgrade to Backbone.

There is none. Subscriptions cover hosting, the AI tools, and email. No ads, no selling your data, no VC growth treadmill.

Can I cancel any time?

Yes. Cancel anytime from Billing and access runs to the end of the paid period. For annual plans, email support within 30 days and we will make it right.

Is my payment secure?

Checkout runs entirely on Stripe. Your card details go straight to Stripe and never touch our servers.

A working network engineer -- not a faceless startup. New questions, labs, and tools ship every week.

Do I need an account to try it?

No. Try a few practice questions or a Route Zero run first. Sign up for a free account when you want to save streaks, rank, and progress.

VLSM: Subnetting a Network Without Wasting Addresses | Reload in 5

A worked example of variable-length subnet masking -- fitting different-sized subnets into one address block.

Practice free · Network engineering tools