In this scenario, what are two requirements for the VLAN ID?

FortiGate is operating in NAT mode and is configured with two virtual LAN (VLAN) subinterfaces added to the same physical interface.

In this scenario, what are two requirements for the VLAN ID? (Choose two.)
A . The two VLAN subinterfaces can have the same VLAN ID, only if they have IP addresses in the same subnet.
B . The two VLAN subinterfaces can have the same VLAN ID, only if they belong to different VDOMs.
C . The two VLAN subinterfaces must have different VLAN IDs.
D . The two VLAN subinterfaces can have the same VLAN ID, only if they have IP addresses in
different subnets.

Answer: B,C

Explanation:

B. The two VLAN subinterfaces can have the same VLAN ID, only if they belong to different VDOMs.

C. The two VLAN subinterfaces must have different VLAN IDs. https://community.fortinet.com/t5/FortiGate/Technical-Note-How-to-use-emac-vlan-to-share-the-same-VL AN/ta-p/192843?externalID=FD43883

Each interface (physical or VLAN) can belong to only one VDOM.

Meaning that sub-interfaces (VLANs) from the same physical interface can have the same VLAN ID as

long as they are not assign to the same VDOM.

VLAN

https://community.fortinet.com/t5/FortiGate/Technical-Tip-rules-about-VLAN-configuration-and-VDOM-interface/ta-p/197640

* VLANs can be created on any physical or aggregate (802.3ad) interfaces

– The same VLAN number cannot be configured twice on the same physical interface

– The same VLAN number can be used on different physical interfaces

– The usable VLAN ID range is from 1 to 4094

* VDOM interface assignment

– Two VDOMs cannot share the same interface or VLAN

– A VLAN sub-interface can belong to a different VDOM than the physical interface it is attached to.