Netpractice 42 Tutorial [2026 Edition]

This guide will show you how to solve the puzzles. You will understand the math behind the answers. 💻 What is NetPractice?

Draw logical circles around groups of devices that are directly connected (same switch, or directly connected to a router interface without another router in between). Devices within the same logical circle must be on the . Look at already-assigned IPs to figure out each subnet's network range.

Many students get stuck because they treat it like a guessing game. NetPractice is pure logic. Let me walk you through exactly how to think about it. netpractice 42 tutorial

What or failed condition is the simulator showing?

: Ensure devices on the same switch have overlapping network ranges. This guide will show you how to solve the puzzles

Keep this table handy while solving levels to quickly identify host limits and masks: Subnet Mask Usable Hosts 255.255.255.252 Ideal for point-to-point router links. /29 255.255.255.248 Small networks. /28 255.255.255.240 Commonly seen in mid-game levels. /26 255.255.255.192 Watch out for overlapping ranges here. /24 255.255.255.0 Standard, easiest to calculate. 4. Common Pitfalls and How to Avoid Them

Two devices can only communicate directly if they share the same network ID (after applying their respective subnet masks). Draw logical circles around groups of devices that

Between two routers, you almost always see a /30 subnet mask. Example: 10.0.0.0/30

If you assign a host IP that equals the network ID or broadcast, the exercise will fail.

PC → Switch → Router A → Router B → Switch → PC. Advanced Levels: Troubleshooting Problem: Packets aren't reaching the destination. Checklist: Are the cables connected correctly? Are the IPs in the correct subnet? Is the default gateway configured? Does the router have an IP on both networks it connects? 4. Pro Tips for Success