Which statement best describes the function of a VLAN in a LAN?

Which statement best describes the function of a VLAN in a LAN?

• A. It increases the size of a single broadcast domain.
• B. It routes traffic between VLANs by default.
• C. It creates multiple IP subnets across VLANs.
• D. It creates separate broadcast domains within the same physical network.

Answer: (D)

Segmenting a LAN with VLANs creates separate broadcast domains. Each VLAN acts like its own logical LAN, so broadcast traffic from devices in one VLAN stays within that VLAN and doesn’t reach devices in other VLANs—even though all the devices may share the same physical switches. This containment reduces unnecessary traffic and helps with security and traffic management. Inter-VLAN communication isn’t automatic; routing between VLANs requires a router or a layer 3 switch (inter-VLAN routing). While it’s common for different VLANs to be assigned different IP subnets, the defining function is the creation of distinct broadcast domains within the same physical network.

Segmenting a LAN with VLANs creates separate broadcast domains. Each VLAN acts like its own logical LAN, so broadcast traffic from devices in one VLAN stays within that VLAN and doesn’t reach devices in other VLANs—even though all the devices may share the same physical switches. This containment reduces unnecessary traffic and helps with security and traffic management.

Inter-VLAN communication isn’t automatic; routing between VLANs requires a router or a layer 3 switch (inter-VLAN routing). While it’s common for different VLANs to be assigned different IP subnets, the defining function is the creation of distinct broadcast domains within the same physical network.