FCSS_NST_SE-7.6 Practice Questions

To establish a functional Security Fabric, specific network and configuration prerequisites must be met to ensure nodes can communicate, authorize, and share telemetry data:

A.  

TCP port 8013 is the dedicated port for FortiTelemetry (Fabric) communication. If firewalls (intermediate or local) block this port, the Fabric connection between the root and downstream FortiGates will fail.

D.  

Security Fabric relies on a trust relationship. When a downstream device attempts to join, it appears in the Root FortiGate ' s dashboard. The administrator must manually authorize this device (unless pre-authorized via serial number) to allow it to join the Fabric topology.

E.  

The interface on the Root (upstream) FortiGate that faces the downstream devices must have the " Security Fabric Connection " (formerly CAPWAP/FortiTelemetry) administrative access setting enabled. Without this, the interface will not listen for or accept Fabric connection requests.

Why other options are incorrect:

B: Neighbor Discovery uses standard multicast/broadcast or static settings; changing the port is not a standard requirement.

C: FortiGates can participate in the Security Fabric in either NAT or Transparent mode; Transparent mode is not a mandatory requirement for the Fabric itself.

The study guide states:

“FortiGate categorizes an entry in the session table as an ephemeral session when it is a TCP session that is not fully established (three-way handshake not completed), or when it is a UDP session with only one packet received.”

This directly proves:

A is correct because a UDP session with only one packet received is ephemeral.

C is correct because a TCP session waiting for the SYN/ACK is not fully established , so it is ephemeral. The study guide’s TCP state table shows that the handshake is only completed when the session reaches ESTABLISHED

Why the other options are wrong:

B is wrong because once UDP traffic has been seen in both directions , it is no longer the “single packet received” condition described for ephemeral sessions. The study guide says for UDP: 00 = one way , 01 = both ways

D is wrong because a TCP session waiting for FIN/ACK is already in the closing stage after establishment, not in the “not fully established” stage. The study guide explains that after both sides close the session, FortiGate can keep it briefly in the table in state value 5 for out-of-order packets after FIN/ACK

The reported symptom—users unable to access any websites despite no explicit blocks in the profile—points to systemic connectivity or configuration issues rather than specific URL filtering rules.

Option B (SSL/TLS Inspection): When Deep Inspection is enabled, the FortiGate acts as a Man-in-the-Middle (MitM) and re-signs server certificates using its own C

A.  

If the clients (browsers) do not trust this CA (i.e., the certificate is not installed in their Trusted Root store), they will reject the connection with certificate errors, effectively preventing access to all HTTPS websites.

Option D (DNS): Web browsing relies on DNS resolution . If the configured DNS server is unreachable or failing, the FortiGate (or the client) cannot resolve FQDNs to IP addresses. Consequently, browsers will fail to load any page, resulting in a total loss of web access.

Option E (License): If the FortiGuard Web Filtering license expires, the FortiGate can no longer query the FortiGuard Distribution Network (FDN) for ratings. By default, or if the allow-when-rating-error setting is disabled (a common security practice), the FortiGate will block all web traffic that it cannot rate, often displaying a " Web Filter Service Error " or invalid license page.

Option A is incorrect because clearing the cache only increases latency, it does not block traffic. Option C is incorrect because webfilter-force-off is typically used to disable the service (often allowing traffic to bypass checks if the service is down), rather than blocking it.

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

B.  

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.  

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 C and D .

For D , the session output shows proto=6, which means TCP, and proto_state=01. The study guide explains that for TCP sessions, “the first number (from left to right) is related to the server-side state and is 0 when the session is not subject to any inspection (flow or proxy). … The second digit is the client-side state.” It also shows that value 1 = ESTABLISHED

So proto_state=01 means:

first digit 0 = no inspection

second digit 1 = ESTABLISHED

That confirms the TCP session has been successfully established.

For C , the study guide section “Session for an Authenticated User” states: “Any session for traffic coming from an authenticated user contains the authed flag. Additionally, the username is added to the session information.”

In the exhibit, the session contains user=User1 and an authentication state flag (authd), which indicates the session is associated with an authenticated user.

Why the other options are wrong:

A is wrong because the session did match a firewall policy . The study guide says the session output includes “The ID of the matching policy” In the exhibit, the session shows policy_id=1 , so a firewall policy was matched.

B is wrong because the study guide explains the gwy field as:

first value = gateway to destination

second value = gateway to source The exhibit shows gwy=10.1.0.254/10.1.10.1, so:

gateway to destination = 10.1.0.254

gateway to source = 10.1.10.1

So the verified answers are: C, D .