What is the native VLAN in 802.1Q trunking?

What is the native VLAN in 802.1Q trunking?

• A. The untagged VLAN used for untagged frames
• B. The VLAN with the highest ID on the trunk
• C. The VLAN used for management traffic only
• D. The VLAN that requires tagged frames

Answer: (A)

In 802.1Q trunking, most traffic on a trunk is tagged with a VLAN identifier, but there’s a special VLAN whose frames travel untagged. This is the native VLAN. It’s the VLAN designated to carry untagged frames across the trunk, providing compatibility for devices or configurations that don’t tag frames. You can configure which VLAN serves as the native VLAN, and while many setups default to VLAN 1, changing it is common for security or segmentation reasons. If the native VLAN isn’t consistent on both ends of the trunk, untagged frames can be misinterpreted, leading to traffic being delivered to the wrong VLAN. So, the native VLAN is the untagged VLAN used for untagged frames on the trunk.

In 802.1Q trunking, most traffic on a trunk is tagged with a VLAN identifier, but there’s a special VLAN whose frames travel untagged. This is the native VLAN. It’s the VLAN designated to carry untagged frames across the trunk, providing compatibility for devices or configurations that don’t tag frames. You can configure which VLAN serves as the native VLAN, and while many setups default to VLAN 1, changing it is common for security or segmentation reasons. If the native VLAN isn’t consistent on both ends of the trunk, untagged frames can be misinterpreted, leading to traffic being delivered to the wrong VLAN. So, the native VLAN is the untagged VLAN used for untagged frames on the trunk.