Computer Networking · Intermediate level

Intermediate level · Module 3: Switching and VLANs · Lesson 2 of 3

VLANs and Trunks

Split one physical network into several logical ones.

In this lesson you will

  • Configure VLANs and access ports
  • Configure trunk ports

Key concepts

VLANaccess porttrunk port802.1Q

The lesson

A VLAN is a separate broadcast domain on shared switches. Devices in different VLANs cannot talk without a router.

Access ports belong to one VLAN and connect end devices. Trunk ports carry several VLANs between switches and routers, tagging frames with 802.1Q.

Put unused ports in an unused VLAN and shut them down.

Step by step

  1. Create VLANs.
  2. Assign access ports.
  3. Configure a trunk.
  4. Test isolation between VLANs.

Practice activity

Configure the VLANs and trunks in Packet Tracer.

Expected result: VLANs working with isolation confirmed.

Check your understanding

  1. What carries several VLANs between switches?

    Show answer

    A trunk port.

  2. Can devices in different VLANs communicate without a router?

    Show answer

    No.

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