Which statement best describes VLANs regarding broadcast domains?

Which statement best describes VLANs regarding broadcast domains?

• A. VLANs create a single shared broadcast domain across the entire network
• B. VLANs segment broadcast domains so each VLAN has its own broadcast domain
• C. VLANs eliminate all broadcasts
• D. VLANs only affect collision domains

Answer: (B)

VLANs create separate broadcast domains by grouping switches’ ports into distinct logical networks. Within a single VLAN, a broadcast frame is heard by every device in that VLAN, but it is not forwarded to devices in other VLANs. To move traffic between VLANs, you need a router or a Layer 3 switch to perform inter-VLAN routing. This behavior—broadcasts contained within each VLAN, with inter-VLAN communication requiring routing—is the defining characteristic of how VLANs handle broadcast domains. Therefore, the best description is that VLANs segment broadcast domains so each VLAN has its own broadcast domain. The other statements don’t fit: a single shared broadcast domain would ignore VLAN separation; VLANs do not eliminate all broadcasts, they localize them to each VLAN; and VLANs concern broadcast domain isolation rather than only collision domains.

VLANs create separate broadcast domains by grouping switches’ ports into distinct logical networks. Within a single VLAN, a broadcast frame is heard by every device in that VLAN, but it is not forwarded to devices in other VLANs. To move traffic between VLANs, you need a router or a Layer 3 switch to perform inter-VLAN routing. This behavior—broadcasts contained within each VLAN, with inter-VLAN communication requiring routing—is the defining characteristic of how VLANs handle broadcast domains. Therefore, the best description is that VLANs segment broadcast domains so each VLAN has its own broadcast domain. The other statements don’t fit: a single shared broadcast domain would ignore VLAN separation; VLANs do not eliminate all broadcasts, they localize them to each VLAN; and VLANs concern broadcast domain isolation rather than only collision domains.