What FCSS_LED_AR-7.6 Questions and Answers feature?

From the FortiManager NAC policy:

Category =Device

Match criteria includeMAC addressandOperating System = Linux

Action =Assign VLAN “Students”

From the FortiGate CLI:

diagnose switch-controller switch-info mac-table ...

MAC: 70:88:6b:8c:4a:ce VLAN: 4089 Port: port2

diagnose switch-controller mac-device mac onboarding

VLAN 4089 MAC 70:88:6b:8c:4a:ce

So the device is stuck inVLAN 4089, which is theonboarding VLAN. No NAC policy is matched.

For a NAC policy to match, FortiGate needsdevice-identity information, which comes fromdevice detection on the VLAN / FortiLink interfaceplus theattributes that the policy expects(OS, MAC, etc.).

A. Device detection is not enabled on VLAN 4089.

If device detection is disabled on the interface/VLAN where the endpoint lives, FortiGate cannot learn OS / device info.

Without this, the NAC engine cannot compare against the NAC policy (which relies on OS and other attributes), so the device remains in the onboarding VLAN.✅This is a valid root cause.

B. The device operating system detected by FortiGate is not Linux.

The NAC policy explicitly requiresOperating System = Linux.

If the endpoint is actually Windows/macOS, or the OS fingerprint is still “Unknown”, the policy will never match, and the device stays in onboarding.✅Also a valid reason.

C. Management communication between FortiGate and FortiSwitch is down.

CLI output (switch-info mac-table and mac-device) proves FortiGate is talking to the switch and sees MAC/VLAN/port information.❌Not a valid reason.

D. The MAC address configured on the NAC policy is incorrect.

The exhibits show the MAC in the NAC policy matches the MAC appearing in the MAC table.❌Not the cause here.

The correct answers are A and B.

The LAN Edge 7.6 Architect study guide explains that when LDAP is the back-end server, CHAP, MS-CHAP, and MS-CHAPv2 do not work because the client sends a one-way password hash, while LDAP expects the actual password:

“If FortiGate is configured to authenticate clients using a remote LDAP server, VPN and wireless clients using CHAP schemes are not able to authenticate... The reason is that during CHAP, MS-CHAP, and MS-CHAPv2 authentication, a client sends a one-way hash of the password. However, the LDAP server, which is on the back end, is expecting the password itself.”

The same study guide then gives the two valid solutions:

“Two possible methods that you can use to solve the CHAP and LDAP problem are:”

“Use RADIUS: Change your back-end server from LDAP to RADIUS.”

and

“If you are using Windows AD as your LDAP server, an alternative is to use FortiAuthenticator as an authentication proxy... You must also configure FortiAuthenticator to log in to the Windows domain using the credentials of a Windows administrator. This adds FortiAuthenticator as a trusted device on the Windows AD domain, allowing FortiAuthenticator to proxy the password hash from the client to the Windows server, using NTLM.”

That directly matches:

A. Enable Windows Active Directory domain authentication on FortiAuthenticator.

B. Configure FortiAuthenticator to use RADIUS instead of LDAP as the back-end authentication server.

The study guide also states this explicitly in the FortiAuthenticator LDAP configuration section:

“If you want FortiAuthenticator to relay CHAP, MS-CHAP, and MS-CHAPv2 authentication to a Windows AD server, you must enable Windows Active Directory Domain Authentication and enter the credentials for a Windows administrator.”

And it separately confirms RADIUS as another supported back-end proxy model:

“You can configure FortiAuthenticator to connect to existing RADIUS servers... If the local user database is not used, FortiAuthenticator proxies RADIUS authentication requests.”

Why the other options are incorrect:

C. Incorrect. RADIUS attribute filtering does not solve the CHAP/MS-CHAPv2 versus LDAP hash problem. The issue is the back-end authentication method, not attribute filtering.

D. Incorrect. Changing from MS-CHAPv2 to CHAP does not fix it, because the study guide says the same limitation applies to CHAP, MS-CHAP, and MS-CHAPv2 when LDAP is the back end

Final verified conclusion:

To enable MS-CHAPv2 authentication in this scenario, the two valid solutions are:

A. Enable Windows Active Directory domain authentication on FortiAuthenticator.

B. Configure FortiAuthenticator to use RADIUS instead of LDAP as the back-end authentication server.

The LAN Edge 7.6 Architect Study Guide identifies the following communication mechanisms between FortiGate and FortiSwitch:

C — FortiLink Protocol (Primary Management Protocol): The study guide states: " FortiLink, also known as the switch controller function, allows FortiGate firewalls to remotely manage FortiSwitch devices. FortiLink defines the management interface and remote management protocol between FortiGate and FortiSwitch, enabling seamless control and integration. " FortiLink is the foundational protocol for the entire management relationship.

B — HTTPS (REST API): The study guide confirms: " FortiGate applies the quarantine-related configuration for the quarantined device to FortiSwitch using the FortiSwitch REST API. " FortiGate communicates with FortiSwitch via HTTPS-based REST API calls for specific configuration pushes such as quarantine enforcement, port configuration, and security policy application.

A — SNMP: SNMP is referenced in the study guide as a management protocol used by FortiGate to monitor and gather status information from FortiSwitch devices. SNMP is a standard network management protocol used for monitoring switch status, which aligns with its role in FortiSwitch management.

Why the other options are wrong:

D is incorrect — CAPWAP (UDP 5246/5247) is the protocol used between FortiGate and FortiAP for wireless AP management, NOT between FortiGate and FortiSwitch. The study guide explicitly states: " FortiGate manages FortiAPs using the CAPWAP protocol. "

E is incorrect — IGMP is an IP multicast group management protocol. It plays no role in the management or control channel between FortiGate and FortiSwitch. It is not mentioned in the LAN Edge 7.6 study guide in the context of FortiSwitch management.