Question

Difficulty: EasySwitching Concepts and VLANs

A network technician is configuring switches in a small office environment and needs to segment network traffic using Virtual Local Area Networks (VLANs). Which TWO of the following statements correctly describe the primary operational characteristics of VLANs?

  1. VLANs divide a single physical Layer 2 switch into multiple separate logical broadcast domains.Answer
  2. Hosts assigned to different VLANs require a Layer 3 routing mechanism to communicate with each other.Answer
  3. C
    Layer 2 switch ports automatically convert Ethernet frames into Layer 3 IP packets when moving between VLAN ports.
  4. D
    Traffic for all configured VLANs travels across 802.1Q trunk links without adding header tags to the Ethernet frames.
  5. E
    Spanning Tree Protocol automatically selects the switch port with the highest VLAN ID to serve as the root bridge.

Answer

The primary operational characteristics of VLANs are that they divide a single physical switch into multiple separate logical broadcast domains, and hosts on different VLANs require a Layer 3 routing mechanism to communicate.
VLANs logically divide physical switches into distinct broadcast domains, which isolates broadcast traffic to specific groups of ports. Additionally, because hosts in different VLANs reside in separate Layer 2 domains, traffic between them cannot be switched directly at Layer 2 and must be routed using a Layer 3 device.

Step-by-Step Solution

1
Analyze how VLANs affect broadcast domains at Layer 2.
Configuring VLANs partitions a switch's physical ports into isolated logical broadcast domains.
Broadcast frames are restricted to only those ports participating in the same VLAN.
2
Determine how communication occurs between separate VLANs.
Direct Layer 2 switching between different VLANs is restricted.
Traffic must be forwarded to a router or Layer 3 switch perform inter-VLAN routing to cross logical boundaries.

Key Concept

VLAN Segmentation and Inter-VLAN Routing Requirements
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