What differentiates an access port from a trunk port on a switch?

What differentiates an access port from a trunk port on a switch?

• A. Access port carries multiple VLANs; trunk carries a single VLAN
• B. Access port carries a single VLAN; trunk carries multiple VLANs with 802.1Q tagging
• C. Access port is used for WAN; trunk for LAN
• D. Access port uses 802.1Q tagging; trunk does not tag frames

Answer: (B)

The main idea is how VLANs are carried on switch ports. An access port is tied to a single VLAN and typically forwards untagged frames for that VLAN, which is what end devices like PCs usually use. A trunk port, on the other hand, carries traffic for multiple VLANs over one physical link and uses 802.1Q tagging to mark which VLAN each frame belongs to. This is essential for inter-switch links and uplinks to routers, where many VLANs share the same pipe. That’s why the correct choice says an access port carries a single VLAN and a trunk port carries multiple VLANs with 802.1Q tagging. The other statements don’t fit because they describe the opposite behavior or mix up where each port type is used.

The main idea is how VLANs are carried on switch ports. An access port is tied to a single VLAN and typically forwards untagged frames for that VLAN, which is what end devices like PCs usually use. A trunk port, on the other hand, carries traffic for multiple VLANs over one physical link and uses 802.1Q tagging to mark which VLAN each frame belongs to. This is essential for inter-switch links and uplinks to routers, where many VLANs share the same pipe. That’s why the correct choice says an access port carries a single VLAN and a trunk port carries multiple VLANs with 802.1Q tagging. The other statements don’t fit because they describe the opposite behavior or mix up where each port type is used.