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Free module

Networks and the internet

How the internet works: layers, IP addresses, routing, DHCP and DNS, NAT and VPNs, worked in hands-on network labs.

6 lessons285 min lesson

The lessons

Each lesson is free to read in full. Create a free account to run its commands in a live lab and to sit its quizzes and tasks.

  1. 1 · Virtual machine lab

    How data travels in layers (TCP/IP)

    I can place a protocol in its layer.

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  2. 2 · Virtual machine lab

    Addresses and masks: who shares a network

    I can tell if two devices are on the same network.

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  3. 3 · Virtual machine lab

    Following a packet across routers

    I can follow a packet across routers.

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  4. 4 · Virtual machine lab

    Getting an address and a name (DHCP, DNS)

    I can explain how a device gets an address and finds a name.

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  5. 5 · Virtual machine lab

    Many devices, one public address (NAT)

    I can explain how many devices share one address.

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  6. 6 · Virtual machine lab

    What a VPN tunnel protects (WireGuard)

    I can explain what a VPN protects.

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Worked in a real lab

Every lesson of this module is worked in a lab started for you alone. The labs it uses:

Teaching a class? Set this module for your students with a teacher guide, marked assignments and a lab for every student.