I'm repeating a "LAN Switching and Wireless" module in college and I'm looking over past exam papers in preparation for the repeat exam. One of the questions is

What is a broadcast domain? Using an example, explain how VLANs affect the broadcast domain.

I know that a broadcast domain is a logical division of a network whereby all nodes can reach each-other on the data-link layer by broadcast. And I realise that each VLAN is essentially its own broadcast domain. But I don't know what example I could give that could answer this question properly.

1 Answer 1


Each VLAN creates its own broadcast domain in 1 or more physical switches. If you have a switch taken out of the box it tends to put all ports in vlan 1 so for say a 24 ports the broadcast domain includes all 24 ports. If you were to create a vlan 2 and configure half the ports to be members of vlan 2 you then have 2 broadcast domains each of 12 ports. if you create a vlan 3 and put half the ports that are still in vlan 1 in it you would end up with 3 broadcast domains 2 with 6 ports and another 1 with 12 ports.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.