Based on the FortiOS 7.6 Administrator Guide regarding Fortinet Single Sign-On (FSSO) polling modes, the agentless polling mode has specific technical characteristics:

SMB Protocol Usage (Statement B is True):

In agentless polling mode, the FortiGate unit itself acts as the collector.

It establishes direct connections to the Windows Domain Controllers (DCs) using the SMB (Server Message Block) protocol, typically over TCP port 445, to read the Windows Security Event logs.

This allows FortiGate to parse login event IDs (such as 4768 and 4769) to identify users and their corresponding IP addresses without needing an external collector agent installed on a server.

Workstation Check Support (Statement C is True):

One of the primary limitations of the agentless polling mode compared to the agent-based mode is the lack of workstation verification.

In agentless mode, FortiGate does not perform " workstation checks " or " dead entry checks " . This means it cannot proactively verify if a user is still logged into a specific workstation after the initial logon event is recorded, which can lead to stale entries if a user logs off without a corresponding event being captured.

Why other options are incorrect:

Option A: In agentless mode, FortiGate (the FSSO daemon) performs the collection itself; it does not use the AD server as a " collector agent " in the functional sense of FSSO architecture.

Option D: While FortiGate uses LDAP to retrieve group membership information once a user is identified, it does not " direct " a collector agent to a remote LDAP server, as there is no external collector agent involved in this specific mode.