NSE 4 – FortiGate 6.2 — Question 49

A FortiGate is operating in NAT mode and configured with two virtual LAN (VLAN) subinterfaces added to the physical interface.
In this scenario, which statement about the VLAN IDs is true?

Answer options

• A. The two VLAN sub interfaces can have the same VLAN ID, only if they have IP addresses in different subnets.
• B. The two VLAN sub interfaces must have different VLAN IDs.
• C. The two VLAN sub interfaces can have the same VLAN ID, only if they belong to different VDOMs.
• D. The two VLAN sub interfaces can have the same VLAN ID, only if they have IP addresses in the same subnet.

Correct answer: B

Explanation

The correct answer is B because each VLAN subinterface must have a unique VLAN ID to avoid conflicts and ensure proper traffic separation. Options A, C, and D inaccurately suggest scenarios where VLAN IDs can be shared, which is not permitted in this configuration.