Networking Don't do this

3 VLAN Mistakes That Cost Marks

3 mistakes that cost marks on VLAN questions

Lesson notes

Key points

VLANs need separate switches: Students think each VLAN needs its own switch; actually one switch logically splits ports into separate VLANs.
VLANs can talk directly: Hosts in different VLANs cannot communicate at Layer 2; you need a router or Layer 3 switch.
Access port carries all…: An access port carries one VLAN; a trunk port carries many, tagged with 802.1Q headers.

Takeaway: Each VLAN is its own broadcast domain; crossing VLANs needs routing.

Quick check: What device lets hosts in two different VLANs communicate?

A Layer 2 hub
A router or Layer 3 switch
An access port

VLANs are separate broadcast domains, so traffic between them must be routed.

Lessons like this, for your syllabus.

Short narrated study videos written for your course, level and exam. Free to start.

Get lessons for your own syllabus