Fortinet FCSS_NST_SE-7.6 Fortinet NSE 6 - Network Security 7.6 Support Engineer Exam Practice Test

To understand why Type 5 LSAs (AS External LSAs) are missing from the Link-State Database (LSDB), we must look at how OSPF generates and propagates them:

A. There is no autonomous system border router (ASBR) in the network:

Reason: Type 5 LSAs are exclusively generated by an ASBR to advertise routes redistributed from other protocols (like Static, BGP, or RIP) into the OSPF domain. If no router is configured to redistribute external routes (acting as an ASBR), no Type 5 LSAs are created in the first place.

C. The local router is located in a stub area:

Reason: By definition, a Stub Area (and a Totally Stubby Area) prevents Type 5 LSAs from entering. The Area Border Router (ABR) connecting the stub area to the backbone filters out all Type 5 LSAs to reduce the size of the LSDB and routing table for routers inside that area. Instead, a default route is usually injected.

Why other options are incorrect:

B: While database filtering exists, standard prefix-list filtering typically affects the routing table (RIB) generation, not the underlying LSDB propagation of Type 5 LSAs, or it is less common than the architectural reasons (Stub/No ASBR).

D: IP Protocol 89 is the transport for OSPF itself. If this were blocked, the OSPF adjacency would not form at all, meaning the router would receive no LSAs (Type 1, 2, etc.), not specifically just Type 5.

The partial output from diagnose hardware sysinfo memory provides details on system RAM allocation. According to Fortinet's technical documentation for memory troubleshooting and Linux memory management (which FortiOS is based on):

MemFree is the portion of physical memory not currently allocated to any running process or kernel function. Thus, 708880 kB is available and can be immediately used by user-space programs or system operations.

Inactive refers to pages in the memory cache that were previously in use for I/O or file system buffering but are now not actively referenced. These pages are retained in memory for quick access if needed again, but can be reclaimed for other memory operations if demand increases. The value 98908 kB here represents currently unused cache pages (inactive pages), ready for repurposing or deletion if the system requires more RAM.

Cached represents the total amount of system memory allocated to cache, which includes both active and inactive cache pages. It does not, by itself, represent I/O cache exclusively, nor does "inactive" mean memory “will never be used” as the kernel can re-purpose inactive pages on demand.

The get router info ospf database brief output on FGT-2 clearly indicates that Area 0.0.0.5 is configured as a [Stub] area.

In OSPF, a Stub Area is specifically designed to reduce the size of the Link State Database (LSDB) on internal routers. The primary behavior of a Stub area is that it does not accept Type 5 (AS External) LSAs.

FGT-3 is the ASBR (Autonomous System Border Router) and is importing static routes, which are generated as Type 5 LSAs in the OSPF domain.

FGT-1 acts as the ABR (Area Border Router). Because Area 0.0.0.5 is a Stub area, FGT-1 blocks these Type 5 LSAs from entering Area 0.0.0.5.

Consequently, FGT-2 will not receive the specific external routes advertised by FGT-3. Instead, the ABR (FGT-1) injects a default route (0.0.0.0/0) into the Stub area to allow connectivity to the external world, which is visible in the database output.

While the question text mentions FGT-3 not receiving routes, the definitive configuration shown in the exhibit is the Stub area setting, which directly corresponds to the blocking of Type 5 LSA propagation (Option A).

The administrator is running a packet sniffer with the filter 'udp port 500 or udp port 4500 or esp'. The result is "no output," even though the VPN is attempting to establish (failing).

A. The VPN is configured to use IKE over TCP:

Standard IPsec IKE negotiation uses UDP port 500 (IKE) and UDP port 4500 (NAT-T).

However, if IKEv2 over TCP (RFC 8229) or Fortinet's proprietary IKE over TCP is configured (often used to bypass firewalls that block UDP), the traffic will use TCP (often port 4500 or 443).

The sniffer filter explicitly looks for udp or esp (IP Protocol 50).

If the traffic is encapsulated in TCP, it matches tcp protocol, not udp or esp (raw ESP). Therefore, the sniffer sees zero packets matching the filter.

Why other options are incorrect:

B: esp is a valid argument for diagnose sniffer packet. It is equivalent to filtering for IP protocol 50.

C: If the ISP were blocking traffic, the sniffer (running on the local FortiGate) would still see the outbound packets generated by the FortiGate trying to initiate the connection. "No output" implies the local device isn't even generating packets matching that filter.

D: Mismatched IKE versions would still generate IKE negotiation packets (proposals/errors) that would be captured by the sniffer.

Auxiliary sessions in Fortinet are designed to support ECMP (Equal Cost Multi-Path) and SD-WAN scenarios, allowing sessions to be handled efficiently when traffic needs to be dynamically distributed across multiple links. With the auxiliary session setting enabled, FortiGate creates additional session table entries for each possible path in ECMP or SD-WAN—meaning that if the routing path changes (such as a link failover), a new session can be immediately activated and offloaded to the NP6 network processor for acceleration, ensuring minimal disruption. This greatly benefits high-throughput deployments.

Official documentation specifies that when auxiliary sessions are enabled, FortiGate doesn’t just rely on dynamically creating new sessions after a routing event, it proactively creates sessions for all potential paths. This means that in the event of a route change, two sessions exist and the traffic is quickly re-routed and offloaded, maximizing performance and reliability. Without this feature, multiple paths cannot be efficiently offloaded, and routing changes trigger a single session update, reducing failover performance.

FortiGate HA Troubleshooting and Synchronization Guides

Fortinet Admin Guide: HA Primary Role Retention, Cluster Break-up Due to Out-of-Sync Status

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 CA. 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.

The exhibit for question 4 shows a policy route table entry, and key fields are as follows:

internet service(1) : Fortinet-FortiGuard(1245324,0.0.0.0,0.0.0.0)

According to the Fortinet official documentation, when a policy route is based on Internet Service Database (ISDB) entries, the route entry will specifically mention “internet service,” showing the service being referenced (in this example, Fortinet-FortiGuard). This is fundamentally different from a regular policy route, which is defined by source, destination, and service wildcards without referencing an ISDB signature. A regular policy route's output would not contain the line “internet service.”

Policy routes that use ISDB allow FortiGate to steer traffic for specific well-known services (like FortiGuard, Google, Microsoft) based on traffic pattern recognition, even if the destination IP is dynamic. The matching and route selection follow the ISDB tag and can coexist with static or regular policy routes.

Thus, this entry is correctly and uniquely an ISDB route, as explained in the FortiOS policy routing documentation and ISDB configuration references.

The exhibit displays the output from the diagnose debug rating command on a FortiGate device. This command is used to display information about FortiGuard Web Filtering or other security-related queries performed by FortiGate to FortiGuard servers. Official Fortinet documentation outlines the meaning of each field in the server list. The FortiGate maintains a list of available FortiGuard servers, selecting the optimal server based on factors such as weight, round-trip time (RTT), and regional settings.

The very first entry in the server list after "Server List" is the server FortiGate initially uses, prioritized by factors such as proximity and RTT. Here, 64.26.151.37 is listed first, and the FortiGuard-requests value confirms that this server handled the highest number of requests.

The IPs, weights, and lost/failed counters are monitored for server performance and selection over time. FortiGate's default operational logic is to try the first entry for contract validation and use the next in the list if the first is unavailable or has high latency or packet loss.

There is no direct correlation between the Weight and the number of FortiGuard-requests. The servers with higher or lower weights may still handle different request volumes based on availability and performance.

The TZ (time zone) value's sign (positive or negative) does not affect server preference; it is informational, showing the server's location relative to UTC, not a rating metric.

DNS query results for FortiGuard servers are not shown here, and the provided servers are not returned in DNS query order.

This command and interpretation are detailed in the FortiOS Administration Guide’s section describing FortiGuard server selection and contract validation processes.

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. You must ensure that TCP port 8013 is not blocked along the way:

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. You must authorize the downstream FortiGate on the root FortiGate:

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. You must enable FortiTelemetry on the receiving interface of the upstream FortiGate:

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 diagnose debug authd fsso server command is the primary tool for troubleshooting communication between the FortiGate and the FSSO Collector Agent. This debug output reveals the status of the connection and the reasons for failure. The three most common connectivity issues identified by this debug are:

FortiGate cannot reach the IP address of the collector agent (Option C): The debug will show connection timeouts or "host unreachable" errors if the Layer 3 connectivity is missing.

The connection was refused / Port mismatch (Option B): If the FortiGate can reach the IP but the Collector Agent is not listening on the specified port (default 8000), the debug will display "Connection refused." This often happens if the port configured on the FortiGate does not match the listening port on the agent.

The pre-shared key does not match (Option D): If the IP and Port are correct, the next step is authentication. If the password configured on the FortiGate does not match the one on the Collector Agent, the debug will explicitly show an "Authentication failed" or "password mismatch" error during the handshake.

Note on other options: Option A (SSL) is less common than basic connectivity/auth mismatches. Option E (Group filters) relates to user processing logic, which occurs after connectivity is established.

We must analyze the flags (*, >, S, O, B) and Administrative Distances (AD) shown in the get router info routing-table database exhibit to determine the correct statements.

Analysis for Option A (The BGP route to 10.0.4.0/24 is not in the forwarding information base):

True. Look at the entry for 10.0.4.0/24.

There is an OSPF route: O *> 10.0.4.0/24 [110/2]. The * indicates it is in the FIB, and > indicates it is the selected route.

There is a BGP route: B 10.0.4.0/24 [200/10]. This line lacks the * flag.

Reason: The OSPF route has an Administrative Distance of 110. The BGP route (iBGP) has an AD of 200. Since 110 is lower than 200, OSPF wins, and the BGP route is not installed in the Forwarding Information Base (FIB).

Analysis for Option B (The default static route through 10.200.1.254 is in the forwarding information base):

True. Look at the 0.0.0.0/0 entries.

The first entry is S *> 0.0.0.0/0 [10/0] via 10.200.1.254.

The * flag confirms this specific route is installed in the FIB.

The second static route (via 10.200.2.254) has a higher distance ([20/0]) and no * flag, so it is inactive.

Why C is False: ECMP (Equal Cost Multi-Path) requires routes to have the same cost/priority. Here, one static route has AD 10 and the other has AD 20. They are not equal, so ECMP is not performed.

Why D is False: The routing table database shows active routes, not the raw Link State Advertisement (LSA) database. You cannot determine the number of LSAs received solely from this output.

The get router info bgp summary output lists BGP neighbor status:

Prefix Reception: The "State/PfxRcd" column shows the number of prefixes received from the neighbor—neighbor 100.64.1.254 has "1", confirming option A.

Received Message Count: Under "MsgRcvd", 18 packets have been received from neighbor 100.64.1.254. This matches option C.

The second neighbor 100.64.2.254 is in "Active" state and has received/sent 0 packets, indicating that its TCP connection is NOT established, disproving option B.

There is no indication anywhere that the router is "still calculating" prefixes; "Active" just means no session is established, so option D is incorrect.

Based on the Fortinet FCSS - Network Security 7.6 documents and standard exam content for these specific troubleshooting scenarios, here are the verified answers.

Questions no: 74

Verified Answer: A, C

Comprehensive and Detailed Explanation with all FCSS - Network Security 7.6 documents:

This question typically refers to a session table exhibit showing Local Traffic (traffic originating from or destined to the FortiGate itself, such as management traffic, DNS queries initiated by FortiGate, or dynamic routing updates). These sessions are identified by Policy ID 0 or the absence of a forwarded interface pair (e.g., local flag).

C. FortiGate either initiated the session or the session terminates at FortiGate:

This is the definition of Local Traffic. Unlike Forward Traffic (which passes through the FortiGate from one interface to another), local traffic belongs to the FortiGate's control plane (e.g., an administrator logging in, or the FortiGate connecting to FortiGuard).

In the session table, this is characterized by policy_id=0 or the source/destination being the FortiGate's own IP.

A. FortiGate is performing a security profile inspection using the CPU:

Local traffic and traffic requiring complex handling (like the application notification app_ntf seen in similar exhibits) are processed by the CPU (Kernel) rather than being fully offloaded to the NPU (Network Processor) fast path.

The NPU cannot handle local host traffic (traffic destined to the FortiGate CPU). Therefore, the CPU must process these packets.

Why other options are incorrect:

B: Captive portal redirection involves specific authentication flags and HTTP redirection, usually seen as a forwarding decision, not a completed local session.

D: "Forwarded without inspection" describes an offloaded or fast-pathed session (NP6/NP7), which would not be local traffic and would show hardware offload flags (e.g., np6_0).

To determine the correct statement, we must analyze the specific fields in the diagnose sys session list output provided in the exhibit.

Analyze Option A (The session is offloaded using NP7):

Evidence: The key indicator is the line npu info: flag=0x81/0x81, offload=8/8, ips_offload=1/1.

This specific npu info output format, particularly the offload=8/8 and ips_offload=1/1 counters, is characteristic of NP7 (Network Processor 7) acceleration.

Legacy NP6 processors typically display np6_0 flags or different offload state bitmaps. The NP7 architecture supports full hardware offloading of sessions including IPS (Intrusion Prevention System) processing, which is explicitly shown here as ips_offload. The offload=8/8 indicates that both the original and reply directions are fully offloaded to the NPU.

Analyze Option C (It is a TCP session from 10.9.31.117 to 10.1.0.3):

Evidence: The hook=post line shows the SNAT translation: 10.9.31.117:45388->200.8.57.5:443(10.1.0.3:45388).

Source: 10.9.31.117 (The client).

Destination: 200.8.57.5 (The external server on port 443).

NAT IP: 10.1.0.3 is the IP address the FortiGate uses for Source NAT (SNAT) as traffic leaves the interface. It is not the destination of the session.

Conclusion: This statement is False.

Analyze Option D (The session will expire in one second):

Evidence: The session info line displays expire=3599.

The expire counter indicates how many seconds remain until the session is removed (if no further packets are seen). A value of 3599 seconds indicates the session was just refreshed (likely having a 3600-second timeout) and will expire in approximately one hour, not one second.

Conclusion: This statement is False.

Analyze Option B (Return traffic to the initiator is sent to...):

While the gateway for reply traffic (gwy=.../10.9.31.117) suggests return traffic goes to that IP, Option A provides the definitive technical observation regarding the hardware architecture (NP7) tested in this exam module.

The debug command diagnose debug application fssod -1 reveals the internal processing of the FortiGate Single Sign-On daemon.

Option D (Agentless Polling): The output shows event_id=4768. Event ID 4768 (Kerberos TGT Request) is a Windows Event Log entry. The presence of specific Event IDs in the fssod debug, rather than a generic logon notification, indicates that the system is reading (polling) the Security Event Logs from the Domain Controller. This is characteristic of Agentless Polling Mode (or Collector Agent Polling Mode), where the FortiGate or Collector scrapes logs. In contrast, DC Agent mode intercepts logon calls directly and would typically provide more complete information, including the workstation name.

Option A (Verification): Crucially, the output shows workstation=,, indicating the workstation name field is empty. In Polling Mode, certain Event IDs (like 4768) often do not contain the source workstation's hostname. Without the workstation name, the FortiGate (or Collector) cannot perform a workstation check (WMI/Registry poll) to verify if the user is still logged in. It essentially has to rely on the "dead entry timeout" because active verification is impossible without the target machine's name.

Option B is incorrect because DC Agents reliably capture workstation names. Option C is incorrect because the system cannot poll a workstation it cannot identify.

When the FortiGate enters Conserve Mode due to high memory pressure (specifically reaching the Extreme Threshold at 95% memory usage, or the Red Threshold for proxy traffic), the system prioritizes stability and preventing a system crash (kernel panic).

D. FortiGate begins dropping all new sessions to protect resources:

In Extreme Conserve Mode (95%), the FortiGate kernel acts to preserve the remaining memory for system-critical tasks (like admin access and basic packet forwarding of existing sessions). To achieve this, it drops all new session initiation requests regardless of the inspection type.

In Red Conserve Mode (88%), it specifically drops new sessions that require proxy-based inspection (as these consume the most memory), while often still allowing flow-based traffic.

Among the provided choices, "dropping new sessions" is the only standard protective mechanism FortiOS employs to stop memory usage from climbing further.

Why other options are incorrect:

A: FortiGate does not automatically reboot in conserve mode; it attempts to recover by restricting traffic. (Reboot is a last-resort crash, not a configured action).

B: Inspection modes (Proxy vs. Flow) are defined in firewall policies and cannot be dynamically switched by the system during runtime.

C: The system does not arbitrarily stop "non-essential processes" like logging or AV. Logging is critical for audit trails. While av-failopen can be configured to bypass scanning, the system typically defaults to "Fail-Close" (dropping traffic) rather than stopping the engines themselves.

FortiOS Admin Guide: Static Routing, SNAT Route Change Feature

The correct answer is A. This behavior is dictated by the configuration command set snat-route-change enable shown in Exhibit 1 under config system global.

Routing Change: By changing the priority of route ID 2 from 10 to 0, it becomes lower than route ID 1 (priority 5). In FortiOS, a lower priority value indicates a more preferred route. Consequently, the active route for the destination changes from port1 to port2.

SNAT Implication: The existing session (shown in Exhibit 2) is using Source NAT (SNAT) with the IP address associated with port1 (10.200.1.1). If the traffic were simply switched to port2, the source IP would be incorrect for that interface and the return traffic would likely fail or be dropped.

snat-route-change enable: This specific setting instructs the FortiGate on how to handle established SNAT sessions when a routing change occurs that alters the preferred outgoing interface. When enabled, if a route change forces an SNAT session to a new interface, FortiGate flushes (deletes) the session from the session table. This is necessary because a live TCP session cannot survive a change in its source IP address. The client must initiate a new session, which will then be created using the new correct route (port2) and the corresponding new SNAT IP.

If this setting were disabled, the session would likely remain "sticky" to the original interface (port1) until it closed, provided the route still existed. However, the explicit configuration forces the deletion.