200-301 Question 239
Select 2A network administrator is configuring a switch to connect to multiple servers using a Link Aggregation Group (LAG). The administrator also needs to ensure that VLAN traffic is properly tagged across these links. Which configuration steps should the administrator apply to the switch ports in the LAG?
- A
Set the switch ports participating in the LAG to trunk mode.
- B
Set the switch ports participating in the LAG to access mode.
- C
Assign all switch ports in the LAG to the same VLAN.
- D
Configure the LAG interface to allow the required VLANs.
- E
Assign each switch port in the LAG to a unique VLAN.
Show answer and explanation
Correct answers: A, D
Explanation
To configure a LAG for VLAN traffic, the participating switch ports must be set to trunk mode to carry VLAN tags and allow traffic from multiple VLANs. Additionally, the LAG interface itself must be configured to permit the desired VLANs. Access mode or assigning unique VLANs to individual ports in the LAG would defeat the purpose of aggregation and proper VLAN tagging.
- A. Correct.
Correct. Trunk mode is required to tag VLAN traffic across the links in a LAG, allowing the switch to handle multiple VLANs.
- B. Incorrect.
Incorrect. Access mode only allows a single VLAN on a port, which is unsuitable for carrying tagged VLAN traffic in a LAG.
- C. Incorrect.
Incorrect. While all ports in a LAG must belong to the same group, VLAN tagging requires trunk mode, not assigning all ports to a single VLAN.
- D. Correct.
Correct. The LAG interface must be configured to allow the VLANs that will be carried across the aggregated links.
- E. Incorrect.
Incorrect. Assigning each port in a LAG to a unique VLAN is invalid as all ports in a LAG must share the same configuration for consistent traffic handling.