Which statement about VLAN IDs on bridges is true?

Which statement about VLAN IDs on bridges is true?

• A. VLAN IDs create separate network segments by tagging traffic on trunk links
• B. VLAN IDs assign an IP address
• C. VLAN IDs determine the MTU
• D. VLAN IDs are only for wireless networks

Answer: (A)

VLAN IDs create separate network segments by tagging traffic on trunk links. On a bridge (switch), VLANs partition broadcast domains so that devices in one VLAN do not see broadcasts from another, and a trunk link can carry multiple VLANs at once. Each frame from a trunk carries a VLAN tag that tells the receiving switch which VLAN it belongs to, so it can forward it appropriately while keeping traffic isolated between VLANs. This is the fundamental way a single physical network can support multiple logical networks. VLAN IDs do not assign IP addresses; IP configuration is a layer 3 matter, and while you typically route between VLANs or assign subnets per VLAN, the VLAN tag itself does not set an IP address. VLANs also do not determine the MTU; MTU is a link property, though tagging can add a small header overhead. Finally, VLANs are used in both wired and wireless networks, not just wireless.

VLAN IDs create separate network segments by tagging traffic on trunk links. On a bridge (switch), VLANs partition broadcast domains so that devices in one VLAN do not see broadcasts from another, and a trunk link can carry multiple VLANs at once. Each frame from a trunk carries a VLAN tag that tells the receiving switch which VLAN it belongs to, so it can forward it appropriately while keeping traffic isolated between VLANs. This is the fundamental way a single physical network can support multiple logical networks.

VLAN IDs do not assign IP addresses; IP configuration is a layer 3 matter, and while you typically route between VLANs or assign subnets per VLAN, the VLAN tag itself does not set an IP address. VLANs also do not determine the MTU; MTU is a link property, though tagging can add a small header overhead. Finally, VLANs are used in both wired and wireless networks, not just wireless.