Networking
It is like…
VLANs Explained with One Office Building
A VLAN is like separate departments sharing one office building
Quick check · tap an answer to continue
Lesson notes
Key points
- Picture one building where Finance and Mining Engineering share the floors but each department only hears its own announcements.
- The building is the physical switch, each department is a VLAN, and announcements are broadcasts that stay inside their own VLAN.
- Where it breaks: staff can walk between departments, but frames cannot cross VLANs at all unless a router forwards them at Layer 3.
Definitions
- Inter-VLAN routing
- A Layer 3 device forwarding packets between VLANs, since each VLAN is a separate broadcast domain and IP subnet.
Takeaway: Each VLAN is its own broadcast domain; crossing VLANs needs routing.
Quick check: What device is needed for hosts in two different VLANs to communicate?
- A hub
- A router
- A repeater
VLANs are separate broadcast domains, so traffic between them must be routed at Layer 3.
One buildingThe mappingInter-VLAN routing
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