Which of the following statements correctly describes the result of binding VLAN 20 to interface 1/1 if the interface was previously bound to VLAN 40 and the native VLAN remains 40?

• A. Interface 1/1 is bound to VLAN 20, and native VLAN is 20.
• B. Interface 1/1 is bound to VLAN 20, and native VLAN remains 40.
• C. Interface 1/1 is bound to VLAN 20, and native VLAN is 40.
• D. Interface 1/1 is bound to VLAN 20, and native VLAN changes to 60.

Answer: (C)

On a trunk port, a native VLAN is the VLAN whose frames are sent untagged, while other VLANs are carried as tagged traffic. Binding VLAN 20 to the interface enables that VLAN on the link, typically as tagged traffic, while the native VLAN remains unchanged for untagged frames.

Since the interface’s native VLAN stays at 40, untagged frames on this port continue to belong to VLAN 40. Binding VLAN 20 means that VLAN 20 is carried on the link (as tagged traffic). Put together, the interface is bound to VLAN 20 and the native VLAN is 40.