Ace Your FCSS_NST_SE-7.6 Fortinet Certified Solution Specialist Exam

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.

The correct answers are B and D .

The study guide explains that expectation sessions are pinhole sessions created by session helpers for protocols such as FTP that need additional negotiated connections. It states: “FortiGate created an expectation session and opened the pinhole port for the expected return traffic” and also shows that the firewall “creates an expected (pinhole) session to allow the traffic”

That makes D correct.

For B , the study guide explains the gwy= field in session output: the first value is the gateway to the destination , and the second is the gateway to the source

In the exhibit, the original-direction traffic is DNATed here:

hook=pre dir=org act=dnat 10.171.121.38:0- > 10.200.1.1:60426(10.0.1.10:50365)

So the destination after DNAT is the internal host 10.0.1.10, and the session’s first gwy value corresponds to the next hop toward that destination. That makes B correct.

Why the other options are wrong:

A is wrong because this is an expectation/session-helper behavior, not an IPS-engine-created session. The study guide ties expectation sessions to helpers such as FTP, not IPS.

C is wrong because 10.200.1.1 is the translated address used before DNAT, not the next hop used to forward the original-direction traffic after translation to the internal destination.

So the verified answers are: B, D .