200-301 Question 238
Select 3A network engineer is configuring a switch to connect multiple VLANs across two switches and improve redundancy. They decide to use a Link Aggregation Group (LAG) with two ports and configure the appropriate port settings. Which of the following configurations should be applied to the ports in the LAG and the VLAN settings?
- A
Configure the ports in the LAG as trunk ports to allow multiple VLANs to traverse the link.
- B
Set the ports in the LAG to access mode to ensure VLAN traffic is carried for a specific VLAN only.
- C
Enable the same VLAN on both switches and allow it on the LAG trunk port.
- D
Use dynamic LACP (Link Aggregation Control Protocol) to negotiate the LAG between the switches.
- E
Assign different VLANs to each port in the LAG for better VLAN separation.
Show answer and explanation
Correct answers: A, C, D
Explanation
To connect multiple VLANs across switches using a LAG, the ports in the LAG must be configured as trunk ports to carry traffic for all VLANs. Additionally, the same VLANs must be allowed on both switches for consistent communication. Using dynamic LACP simplifies the setup by negotiating the LAG between switches, ensuring proper operation and redundancy. Access mode and assigning different VLANs to individual ports in the LAG are incorrect as they conflict with LAG's purpose and functionality.
- A. Correct.
Correct: Configuring the ports in the LAG as trunk ports is necessary to allow multiple VLANs to traverse the link.
- B. Incorrect.
Incorrect: Access mode restricts the port to a single VLAN, which defeats the purpose of carrying multiple VLANs over the LAG.
- C. Correct.
Correct: Ensuring the same VLANs are configured and allowed on both switches ensures consistent communication across the LAG.
- D. Correct.
Correct: Using dynamic LACP allows automatic negotiation of the LAG, simplifying the configuration and ensuring compatibility.
- E. Incorrect.
Incorrect: Assigning different VLANs to each port in a LAG disrupts the LAG functionality, as all ports in a LAG must operate as a single logical link.