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Free module

Computer networks

Learn computer networks hands on: subnets, routing, OSPF, BGP, NAT, DHCP, DNS, VLANs and VPNs, in real network labs.

8 lessons435 min lessonCore computer science

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

    Splitting a network into subnets

    I can split a network into subnets.

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  2. 2 · Virtual machine lab

    Telling routers where to send traffic (static routes)

    I can read a routing table and pick the route a packet takes.

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  3. 3 · Virtual machine lab

    How routers find the shortest path (OSPF)

    I can say how OSPF routers learn the network.

    Read the lesson

  4. 4 · Virtual machine lab

    How separate networks swap routes (BGP)

    I can say how two networks share routes with BGP.

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  5. 5 · Virtual machine lab

    Sharing one public address (NAT)

    I can explain how a private host reaches the internet through NAT.

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  6. 6 · Virtual machine lab

    Handing out addresses and names (DHCP, DNS)

    I can explain how a host gets an address and a name.

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  7. 7 · Virtual machine lab

    Keeping groups apart on one switch (VLANs)

    I can keep two groups of hosts apart on one switch.

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  8. 8 · Virtual machine lab

    Joining two sites with a VPN tunnel (WireGuard)

    I can explain how a tunnel joins two sites.

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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.