Which statement best describes the use of a VLAN ID tag?

Which statement best describes the use of a VLAN ID tag?

• A. It defines a network address for VLAN management
• B. It tags frames to indicate association with a specific VLAN
• C. It assigns an IP to a VLAN interface
• D. It disables VLANs on trunk ports

Answer: (B)

VLAN tagging marks Ethernet frames with a VLAN identifier so switches can distinguish traffic when multiple VLANs share a single physical link. This tagging, typically done on trunk ports using 802.1Q, lets frames from different VLANs traverse the same cable while keeping their traffic separated and forwarding decisions correct. On access ports, frames are usually untagged and belong to a single VLAN, whereas trunk ports carry frames with tags (and may carry an untagged frame for a native VLAN). This makes the statement describing tagging frames to indicate their VLAN association the best fit. The other options relate to IP addressing or management interfaces, or describe disabling VLANs, which are not about how VLAN membership is identified in frames.

VLAN tagging marks Ethernet frames with a VLAN identifier so switches can distinguish traffic when multiple VLANs share a single physical link. This tagging, typically done on trunk ports using 802.1Q, lets frames from different VLANs traverse the same cable while keeping their traffic separated and forwarding decisions correct. On access ports, frames are usually untagged and belong to a single VLAN, whereas trunk ports carry frames with tags (and may carry an untagged frame for a native VLAN).

This makes the statement describing tagging frames to indicate their VLAN association the best fit. The other options relate to IP addressing or management interfaces, or describe disabling VLANs, which are not about how VLAN membership is identified in frames.