C. The IP address of the FortiSwitch is 10.12.240.2:This statement is correct based on the exhibit and your clarification. The exhibit lists the "IP Address" as 10.12.240.2 across multiple entries, including ports and VLANs associated with the device "sup-fgt-hw" (FortiSwitch). Your reasoning indicates that this IP is the management address of the FortiSwitch, as it is consistently shown as the IP for the device containing the ports. In Fortinet’s architecture, as described in the NSE 8 study guide, the management IP of a FortiSwitch is typically configured and visible in such configurations, especially when integrated with FortiGate and FortiNAC. The "Device" column labeling "sup-fgt-hw" further supports that this is the FortiSwitch, and the IP 10.12.240.2 is its management address. This aligns with FortiSwitch management and integration details in the NSE 8 study guide.

D. An unknown host is connected to port3:This statement is correct as the exhibit highlights port3 under the "Name" column for the device "sup-fgt-hw" with a "Rogue Host" status in the "Connection" column, an IP address of 10.12.240.2, a Default VLAN of 100, and an Operational Status of "Link Up." In FortiNAC, a "Rogue Host" indicates an unknown or unauthorized device connected to the network, which FortiNAC identifies for further action or isolation. This is consistent with FortiNAC’s capabilities for detecting and classifying unknown devices, as detailed in the NSE 8 study guide under network access control and rogue device detection.

Why A and B are incorrect:

A. A device that is modeled in FortiNAC is connected on VLAN_4093: This is incorrect based on your clarification that there is no device connected on that port—it is simply the default VLAN (4093) for that entry. The exhibit shows VLAN_4093 with a "Not Connected" status and "Link Up" operational status, but no active device connection is indicated. The NSE 8 study guide emphasizes that FortiNAC requires an active connection and device profiling for a device to be considered "connected," which is not evident here for VLAN_4093.

B. Port8 is connected to a FortiGate in FortiLink mode: This is incorrect because the exhibit shows port8 with a "Learned Uplink" status, which, as you noted, refers to any kind of uplink and does not specifically indicate FortiLink mode. FortiLink mode is a specific configuration between FortiGate and FortiSwitch requiring explicit settings, which are not mentioned or implied in the exhibit. The NSE 8 study guide clarifies that FortiLink mode involves distinct configuration details (e.g., FortiLink interfaces), which are absent here.

Fortinet Network Security Expert 8 Study Guide References:

FortiNAC 7.2 Admin Guide (NSE 8): Sections on Device Visibility, VLAN Management, and Rogue Device Detection.

FortiSwitch 7.2 Admin Guide (NSE 8): Sections on FortiLink Configuration, Network Segmentation, and Management IP Configuration.

FortiGate 7.2 Admin Guide (NSE 8): Sections on Integration with FortiNAC and FortiSwitch for Network Security.