NetPractice: Finally Understanding Subnetting

Hi! NetPractice is different from every other 42 project: no code at all. You get ten levels of half-configured network diagrams, and you fill in IP addresses, subnet masks and routes until every packet can reach its destination.

What the levels drill into you

• How an IP address and a subnet mask define a network, and why 255.255.255.252 only leaves two usable hosts,
• Why two interfaces on the same wire must share a subnet — and two networks behind a router must not,
• How routing tables and default gateways actually decide where a packet goes next,
• The difference between private and public ranges when traffic crosses the internet.

Why I ended up liking it

Before NetPractice, subnetting was something I half-remembered from theory. After doing the levels (and the final ones under evaluation pressure, where you solve them live with a time limit), reading a CIDR like /26 became as natural as reading decimal. It paid off almost immediately — the knowledge carried straight into configuring servers, Docker networks and the ft_irc project later on.