Which command, when issued on a trunking interface, would set a VLAN that is not to be given an 802.1q tag?
- SW2(config-if)# switchport trunk native vlan 99
- SW2(config-if)# switchport trunk no-tagging vlan 99
- SW2(config-if)# switchport native vlan 99
- SW2(config-if)# trunk native vlan 99
Explanation: In the IEEE 802.1Q trunking protocol, all frames are typically assigned a 4-byte tag to identify their VLAN membership as they traverse a trunk link. However, there is a special designation known as the native VLAN. By default, frames belonging to the native VLAN are carried over the trunk link untagged (without an 802.1Q header).
While the default native VLAN is VLAN 1, network administrators often change it to a different ID for security purposes. To configure a specific VLAN—such as VLAN 99—to be the native VLAN that is not given an 802.1Q tag, you must use the command switchport trunk native vlan 99 while in interface configuration mode. Once this is set, the switch will transmit traffic for VLAN 99 without a tag and expect to receive untagged traffic from the neighboring switch for that same VLAN. The other options provided do not follow the standard Cisco IOS command syntax.
Related exam: Modules 1 – 7: Checkpoint Exam: Network Switching Answers (CCNP ENCOR v9)
