Fortinet Fortinet NSE 6 - Network Security 7.6 Support Engineer FCSS_NST_SE-7.6 Exam Dumps: Updated Questions & Answers (May 2026)

The correct answer is A .

The debug flow shows:

traffic is going to TCP port 211

FortiGate logs run helper-ftp(dir=original)

The study guide explains exactly what that message means:

“In this example, the run helper-ftp message indicates that the FTP session helper is being used.”

Under normal proxy-based inspection, protocol handling is controlled by Protocol Options . The FortiOS administration guide states:

“Protocol port mapping only works with proxy-based inspection.” and “The ports can be modified to inspect any port with flowing traffic.”

So if the policy is configured for proxy-based inspection but the debug still shows the FTP session helper on port 211, the most likely explanation is that the FTP protocol mapping in Protocol Options is broad enough to match unexpectedly, such as being mapped to Any . That would cause FortiGate to identify the traffic as FTP and invoke the helper.

Why the other options are wrong:

B is wrong because SSL deep inspection is unrelated to this debug. The traffic shown is plain TCP/211 , and the key message is about the FTP helper , not SSL decryption.

C is wrong because if FTP had not been mapped to port 211, FortiGate would be less likely to treat this traffic as FTP. The observed run helper-ftp indicates FTP handling is being triggered.

D is wrong because low-memory conserve behavior would typically cause inspection bypass or blocking behavior, not specifically the run helper-ftp message. The study guide’s helper example ties this message to session-helper use, not memory shortage.

So the verified answer is: A .

The correct answer is B .

The study guide explicitly states: “IKE version 2 does not interoperate with IKE version 1, but they share enough of the header format that both versions can unambiguously operate over the same UDP port.”

That directly proves B .

Why the other options are wrong:

A is wrong because the study guide shows authentication methods as Asymmetric for IKEv2 and Symmetric for IKEv1

C is wrong because the study guide does not say they use the same TCP port; instead, it specifically says they can operate over the same UDP port

D is wrong because the study guide states: “IKEv2 does not use the concept of phase 1 or phase 2” , even though FortiOS CLI/GUI still uses those terms for configuration purposes

The correct answer is C. 64.26.151.37 .

The study guide explains the FortiGuard flags shown by diagnose debug rating:

D = Default

I = Initial

T = Timing

F = Failed and specifically: “F = The server is down”

So even though 121.111.236.179 has the lowest RTT in the exhibit, it has the F flag, meaning FortiGate considers that server failed/down , so it will not be chosen.

To determine which active server is selected, the FortiOS administration guide states:

“The server list is sorted first by weight. The server with the smallest RTT appears at the top of the list regardless of weight. … Therefore the top position in the list is selected based on RTT while the other positions are based on weight.”

Among the valid, non-failed choices in the exhibit:

64.26.151.37 → RTT 45

209.22.147.36 → RTT 103

96.45.33.65 → RTT 144

208.91.112.194 → RTT 107

The active server with the lowest RTT is 64.26.151.37 , so that is the server FortiGate will choose.

So the verified answer is: C .

The correct answers are A and C .

The exhibit shows that preserve-session-route is enabled on port1:

config system interface

edit " port1 "

set preserve-session-route enable

next

end

The study guide explains the effect of this setting exactly:

“enable: FortiGate marks existing session routing information as persistent, and applies only the modified routes to new sessions”

It also states:

“The current route must still be present in the FIB. Otherwise, FortiGate flags the session as dirty and reevaluates it”

And the same page further clarifies:

“If you enable this setting, sessions passing through that interface continue to pass without being affected by the routing changes. The routing changes apply only to new sessions. If the route is removed from the FIB, then FortiGate must flag the session as dirty, flush its gateway information, and reevaluate the session.”

This proves:

A is correct because with preserve-session-route enable, existing sessions are normally preserved and routing changes apply only to new sessions.

C is correct because the session remains unchanged unless the current route is removed from the FIB/routing table, in which case FortiGate dirties and reevaluates the session.

Why the other options are wrong:

B is wrong because when the active route is removed, FortiGate does not simply mark the session dirty and stop there. The study guide says it “flags the session as dirty and reevaluates it” , which means route lookup happens again.

D is wrong because the session does change if the active route is removed. FortiGate flushes gateway information and reevaluates the session.

So the verified answers are: A, C .

To capture encrypted IPsec phase 2 (ESP) traffic between two FortiGate devices, the correct protocol filter to use is ip proto 50. According to the Fortinet official sniffing and debugging documentation, ESP (Encapsulating Security Payload) is used for encrypted phase 2 payload transfer and always uses IP protocol number 50. Running the command diagnose sniffer packet any ' ip proto 50 '  captures only ESP packets, which represent the encrypted traffic—whether originating or transiting the device.

If there is no NAT device between FortiGates, ESP is not encapsulated in UDP (thus not on UDP port 4500; if NAT-T were required, packets would be UDP-encapsulated, but the scenario explicitly says NAT is not in use). UDP port 500 is for IKE control (negotiation) traffic, and AH (Authentication Header, ip proto 51) is not used for encryption in standard IPsec phase 2 with ESP.

This matches the official CLI reference from Fortinet for VPN and traffic analysis.

**

To determine the cause of the failure, we must analyze the IKEv2 debug output provided in the exhibit (image_ad3dc6.jpg):

Identify the Negotiation Phase:

The debug log shows: responder received CREATE_CHILD exchange.

In IKEv2, the CREATE_CHILD_SA exchange is used to create new Child SAs (Phase 2) or to rekey existing ones.

The fact that the tunnel was previously " brought up successfully " implies the initial IKE SA (Phase 1) is stable, and this error is occurring specifically during a rekey event, which often involves Perfect Forward Secrecy (PFS).

Analyze the Proposals (The Mismatch):

Incoming Proposal (Remote Peer):

The remote peer sends a proposal containing two Diffie-Hellman groups: type=DH_GROUP, val=MODP2048 (Group 14) and type=DH_GROUP, val=MODP1536 (Group 5).

My Proposal (Local FortiGate):

The local FortiGate configuration expects: type=DH_GROUP, val=MODP3072 (Group 15).

Result of the Negotiation:

The debug output concludes with: no proposal chosen and Negotiate SA Error.

This error occurs because the local FortiGate cannot find a common Diffie-Hellman group between what it requires (Group 15) and what the peer is offering (Groups 14 or 5).

While this is technically a mismatch occurring during the Phase 2 (Child SA) creation, " A Diffie-Hellman mismatch " (Option A) is the precise root cause identified in the logs.

Why other options are incorrect:

B: The log shows received create-child request, confirming that UDP traffic is reaching the device and is not blocked.

C: The failure is in the CREATE_CHILD exchange (Phase 2/Rekey), not the IKE_SA_INIT or IKE_AUTH (Phase 1) exchanges.

D: While the mismatch is occurring within the Phase 2 definitions, Option A is the specific technical reason for the no proposal chosen error shown in the DH_GROUP lines.

According to the official Fortinet documentation (Technical Tip: Useful FSSO Commands), heartbeat messages play a crucial role in communication between the FSSO Collector Agent and FortiGate. These messages are regularly sent from the Collector Agent to verify its status, maintain session awareness, and confirm connectivity between the authentication infrastructure and FortiGate appliances.

Option B is confirmed by Fortinet, as the collector agent logs on Windows or its management console will specifically note heartbeat events, connection status, and any issues maintaining contact with FortiGate units.

Option C is validated by both official CLI documentation and the technical tip linked. On FortiGate, heartbeat messages from the collector agent are visible using real-time debug tools such as diagnose debug application authd or FSSO-specific commands. These enable administrators to monitor live logon states, session status, and connection health directly from the FortiGate CLI. The debug stream shows heartbeats received and their effect on active logons, associating health monitoring with active sessions.

Heartbeat operation is fully automated once FSSO is set up—there is no requirement for manual enablement or configuration, aligning with Fortinet’s philosophy of seamless integration and centralized management across the Security Fabric. This ensures that both FortiGate and the collector agent can quickly and reliably detect any miscommunication or outage, addressing authentication issues proactively.

The correct answer is A .

The debug output is for an HTTPS request and shows a hostname value. The study guide explains that with SSL certificate inspection, FortiGate extracts the FQDN from either:

“TLS extension server name indication (SNI)”

“SSL certificate common name (CN)”

So the hostname shown in the real-time web-filter debug can be derived from the SNI in the client request or, if needed, from the CN in the server certificate. That makes A correct.

Why the other options are wrong:

B is wrong because the study-guide example for web-filter real-time debug explicitly says: “This slide shows an example of real-time debug output when the URL to categorize isn ' t in the FortiGuard cache.” In these debugs, cat=255 appears before the final lookup result, so this does not indicate a local-cache hit.

C is wrong because ftgd-allow is the action , not the profile name. The debug line shows the action as action=9 (ftgd-allow) while the profile shown is profile= ' default ' . FortiOS web-filter logs also use the profile field separately from the action field

D is wrong because the final category shown is url_cat=52 , not 255. The study guide’s example shows the same pattern: an initial cat=255 in the request line, followed by the resolved result cat=52 url_cat=52

So the verified answer is: A .