VLANs (virtual local area networks) allow networks to be segmented logically even if they are physically connected to the same switch. VLANs are configured by tagging Ethernet packets with an identifier to specify which network segment they belong to. This allows networks to be reconfigured without changing physical cabling and provides increased security by restricting access between network segments. Issues can arise from longer tagged frames being dropped by older switches that don't support tagging.

1. Virtual local area networks VLAN

2. Basic switched networking

3. VLAN network

4. Why VLANs Security Ex. everybody may connect to the network, but has only acces to internet. Change network topology without physical changes

5. Possibility of dynamic changes between VLANs

6. Switching (layer 2) instead of routing (layer 3) - better performance

7. How it works Different network segments or ”broadcast domains”

8. Two basic ways Ethernet packages are tagged (IEEE 802.1Q)

9. VLANs based on the physical port of the switch. VLANs chosen dynamically, by MAC address or by switch port.