LAN Switching: VLANs, Trunks and Spanning Tree

Configure, verify and troubleshoot Cisco switched networks: VLANs, 802.1Q trunks, inter-VLAN routing, Rapid PVST+ and EtherChannel, built and tested in Packet Tracer.

Intermediate · Networking · about 12 hours · 4 modules · certificate on completion

Taught by Carlòs Ramirèz, Ismaìlè Rahimovì, AI Learning Companions.

About this course

Switches connect almost every wired device in an office, school or data centre, and how they're configured decides whether the network is fast, secure and resilient. In this course you'll configure Cisco switches the way network engineers do. You'll see how a switch learns and forwards frames and manage it from the IOS command line, then divide the network into VLANs, carry them between switches on 802.1Q trunks with a safe native VLAN, and route between them, first with router-on-a-stick and then with switch virtual interfaces on a Layer 3 switch. Finally you'll add redundant links without creating loops: you'll work out how spanning tree chooses its root bridge and blocks ports, tune Rapid PVST+, protect edge ports with PortFast and BPDU guard, and bundle links into EtherChannels with LACP.

Every lesson shows the commands step by step in Cisco Packet Tracer, with the output you should see, and every module ends with a lab your instructor reviews against real show command output. The course ends with a project in which you build, test and document the switched network for a two-floor office. It follows the Network Access topics in Cisco's published CCNA (200-301) exam topics.

What you'll learn

  • Explain how switches learn, flood and forward frames, and manage a Cisco switch from its command line
  • Create VLANs, assign access ports, and carry VLANs between switches on 802.1Q trunks with a safe native VLAN
  • Route between VLANs with router-on-a-stick and with switch virtual interfaces on a Layer 3 switch
  • Control Rapid PVST+: place the root bridge, read port roles, and protect edge ports with PortFast and BPDU guard
  • Bundle links into EtherChannels with LACP, and verify and troubleshoot switched networks with show commands

Skills you'll gain

Cisco IOS switch configuration, VLANs, 802.1Q trunking, Inter-VLAN routing, Layer 3 switching, Spanning Tree Protocol, Rapid PVST+, EtherChannel and LACP, Switch troubleshooting, Cisco Packet Tracer

Tools

Cisco Packet Tracer, Cisco IOS

Before you start

Networking basics: what switches, routers, MAC addresses and IP addresses are, and how to subnet a /24 (Networking Fundamentals and IP Addressing and Subnetting cover them). You need Cisco Packet Tracer (free with a Cisco Networking Academy account).

Aligned with: Cisco CCNA (200-301) exam topics: Network Access

Modules

  1. Switch operation and the switch CLI

    Look inside a switch's forwarding decisions and its MAC address table, and get fluent with the IOS commands for managing and configuring a Cisco switch.

    • How a switch forwards frames (12 min)
    • Managing a switch from the command line (12 min)
    • Hands-on lab: Set up and map a two-switch LAN

  2. VLANs and trunks

    Split a switched network into VLANs, carry them between switches on 802.1Q trunks, and find the faults that most often break them.

    • VLANs and access ports (12 min)
    • 802.1Q trunks and the native VLAN (14 min)
    • Troubleshooting VLANs and trunks (12 min)
    • Hands-on lab: VLANs across two switches

  3. Routing between VLANs

    Give each VLAN a gateway and route between them: first with a router on a trunk (router-on-a-stick), then with switch virtual interfaces on a Layer 3 switch.

    • Router-on-a-stick (12 min)
    • Layer 3 switches and switch virtual interfaces (12 min)
    • Hands-on lab: Route between VLANs two ways

  4. Spanning tree and EtherChannel

    Add redundant links without loops: see how spanning tree chooses a root and blocks ports, tune Rapid PVST+, protect edge ports, and bundle links with LACP.

    • Why loops happen and how spanning tree stops them (14 min)
    • Rapid PVST+: root bridges, PortFast and BPDU guard (14 min)
    • EtherChannel with LACP (12 min)
    • Hands-on lab: Resilient links: Rapid PVST+, edge ports and EtherChannel

Project: Build a switched network for a two-floor office

Design, build and document the switched network for a two-floor office in Packet Tracer. Each floor has an access switch (a 2960) with staff PCs in VLAN 10 (192.168.10.0/24) and guest PCs in VLAN 20 (192.168.20.0/24). Both access switches connect to a Layer 3 distribution switch (a 3560-24PS) over two-link LACP EtherChannel trunks, and the two access switches are also linked to each other, so there's a redundant path. The distribution switch routes between the VLANs with SVIs, using .1 on each subnet, and the switches' management addresses are in VLAN 100 (192.168.100.0/24). Use VLAN 99 as the native VLAN on every trunk, allow only the VLANs each trunk needs, make the distribution switch the Rapid PVST+ root for every VLAN, protect every host port with PortFast and BPDU guard, label every link with a description, and shut down unused ports. Then prove it all works, explain which port spanning tree blocks and why, and show that the network survives the loss of a link.

Part of

Cisco, CCNA, Cisco IOS and Cisco Packet Tracer are trademarks of Cisco Systems, Inc. This course is independent: Cisco hasn't made or endorsed it, and it doesn't give you a Cisco certification.

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