NSE 4 – FortiGate 6.0 — Question 95

A FortiGate is operating in NAT mode and configured with two virtual LAN (VLAN) sub interfaces added to the physical interface.
Which statements about the VLAN sub interfaces can have the same VLAN ID, only if they have IP addresses in different subnets.

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 in NAT mode on a FortiGate device, each VLAN sub interface must have a unique VLAN ID to ensure proper traffic separation. Options A, C, and D are incorrect as they suggest scenarios where the VLAN IDs can be the same, which is not allowed in this configuration.