Free course

Networking Foundations Course

Learn how local networks and the Internet move data through links, IP addresses, routes, TCP, UDP, ports, NAT, firewalls, and practical diagnostics.

7 modules · 35 lessons · No signup

Prerequisites: Shell Commands

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What you'll learn

Trace one connection from an application through the local network and Internet, inspect each layer, and identify where a failed connection stops.

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Course contents

  1. How networks fit together

    Understand endpoints, links, interfaces, layers, packets, encapsulation, and the complete path.

    1. ✓ What a network is
    2. ✓ LANs, WANs, and the Internet
    3. ✓ Layers and protocols
    4. ✓ Encapsulation and one complete path
    5. ✓ Check your understanding: network models

  2. Local networks

    Follow frames through Ethernet or Wi-Fi using MAC addresses, switches, ARP, and Neighbor Discovery.

    1. ✓ Frames and MAC addresses
    2. ✓ How switches forward frames
    3. ✓ ARP resolves IPv4 neighbors
    4. ✓ IPv6 Neighbor Discovery
    5. ✓ Check your understanding: local networks

  3. IP addresses and subnets

    Read IPv4 and IPv6 addresses, prefixes, subnets, and special address ranges.

    1. ✓ Read an IPv4 address and prefix
    2. ✓ Calculate a subnet boundary
    3. ✓ Recognize special IPv4 ranges
    4. ✓ Read an IPv6 address and prefix
    5. ✓ Check your understanding: IP addressing

  4. Configuration and routing

    Learn how hosts get configuration, choose routes, cross routers, and receive ICMP feedback.

    1. ✓ Get network configuration
    2. ✓ Read the routing table
    3. ✓ Follow routers and hop limits
    4. ✓ Use ICMP, ping, and traceroute
    5. ✓ Check your understanding: configuration and routing

  5. TCP, UDP, ports, and sockets

    Connect application processes through reliable streams or independent datagrams.

    1. ✓ Choose TCP or UDP
    2. ✓ Ports and sockets
    3. ✓ Follow a TCP connection
    4. ✓ Send a UDP datagram
    5. ✓ Check your understanding: transport and ports

  6. NAT, firewalls, and packet size

    Understand translated addresses, stateful filtering, MTU, fragmentation, and path boundaries.

    1. ✓ Understand NAT and port translation
    2. ✓ Firewalls and connection state
    3. ✓ MTU, fragmentation, and Path MTU
    4. ✓ Separate address, route, port, and protocol
    5. ✓ Check your understanding: network boundaries

  7. Diagnose the complete path

    Inspect local state, test each layer, capture packets, and explain a failure with evidence.

    1. ✓ Inspect local network state
    2. ✓ Test one layer at a time
    3. ✓ Capture and read packets
    4. ✓ Diagnose one complete connection
    5. ✓ Check your understanding: diagnose the path