Fortinet Updated FCSS_NST_SE-7.6 Exam Questions and Answers by dawud

The study guide identifies this exact output as an expectation session created by the FTP session helper :

“run helper-ftp” indicates the FTP helper is in use.

“FortiGate created an expectation session and opened the pinhole port for the expected return traffic”

It also explains why this exists:

“Another important function of the session helper is to temporarily create an expected session (or pinhole) for the data channel connection that comes from the server.”

“The session helper automatically creates the session and opens the door for the incoming connection.”

“These incoming TCP sessions use random TCP port numbers.”

That directly proves C is correct.

For A , the exhibit shows expire=23. The study guide explains the expire field as the length of time until the session expires if no matching traffic arrives, and the FortiOS guide states for expectation sessions:

“Expectation sessions usually have a timeout value of 30 seconds. If the communication from the server is not initiated within 30 seconds the expectation session times out and traffic will be denied.”

So with expire=23, FortiGate will allow that expected traffic only for the remaining 23 seconds; after that, it times out and the traffic is denied. That makes A correct.

Why the other options are wrong:

B is not supported . The study guide describes expectation sessions as being created by the session helper from the control-session negotiation, not as independent objects unaffected by the master session.

D is wrong as stated. Even though the output contains policy_id=25, the study guide explicitly says the incoming expected connection is allowed by the expected session itself, “even when no firewall policy allows it.”

The best verified answer is C .

The study guide says that when FortiGate is in conserve mode, it activates protection measures to recover memory space:

“System configuration cannot be changed”

“FortiGate skips quarantine actions (including FortiSandbox analysis)”

It also explains that inspection behavior can be reduced while in conserve mode:

“pass (default): All new sessions pass without inspection until FortiGate switches back to non-conserve mode.”

“The av-failopen setting also applies to flow-based antivirus inspection.”

The FortiOS administration guide summarizes this behavior as:

“This causes functions such as antivirus scanning to change how they operate to reduce the functionality and conserve memory without compromising security.”

That is why C is the closest correct choice: FortiGate can reduce functionality of some processes, especially antivirus-related inspection, to preserve memory.

Why the other options are wrong:

A is wrong because FortiGate does not automatically reboot as a default conserve-mode action. A reboot can be configured through an automation stitch , but that is an optional administrator-defined response, not the built-in conserve-mode behavior

B is wrong because the documentation does not say FortiGate switches from proxy-based inspection to flow-based inspection. Instead, it may pass traffic without inspection depending on av-failopen settings

D is not generally correct for conserve mode . The study guide says FortiGate starts dropping new sessions only when memory usage exceeds the extreme threshold : “If memory usage exceeds the extreme threshold, all new sessions that require inspection (flow-based or proxy-based) are blocked.”

So the verified answer is: C .

Intermittent behavior (working sometimes, failing others) points to resource or connectivity fluctuations rather than static misconfigurations.

B. Check that FortiGate is not entering conserve mode:

Reason: When FortiGate enters Conserve Mode (due to high memory usage), it changes its inspection behavior to save resources. Depending on the av-failopen setting, it may either bypass inspection (allowing blocked sites) or drop traffic (blocking valid sites) temporarily until memory recovers. This flapping between states causes intermittent filtering issues.

D. Check that the communication between FortiGate and FortiGuard is stable:

Reason: The Web Filter engine relies on real-time queries to the FortiGuard Distribution Network (FDN) to categorize URLs that are not in the local cache. If the internet connection or the specific path to FortiGuard is unstable (packet loss, latency), queries will time out. This results in " Rating Errors, " which can block or allow traffic unpredictably based on the " Allow websites when a rating error occurs " setting.

Why other options are incorrect:

A: A mismatch in inspection mode (e.g., Profile set to Proxy, Policy set to Flow) is a static configuration error. It would typically result in the profile not being selectable or consistently failing/not applying, rather than working intermittently.

C: If the wrong port is mapped (e.g., HTTP on 8080 is not mapped), the inspection engine will consistently ignore traffic on that port. It would not be intermittent.