The correct answer is A.

The study guide explicitly explains the diagnose debug rating table and says that for each server IP, the output shows “The round trip delay”

That means the RTT value represents the time it takes for FortiGate to send a request and receive the reply from that FortiGuard server.

The FortiOS administration guide also confirms this by stating:

“Each server is probed for Round Trip Time (RTT) every two minutes.”

Why the other options are wrong:

B is wrong because packet loss is shown separately by Curr Lost and Total Lost, while RTT is the round-trip delay

C is wrong because license-validation behavior is indicated by flags such as I = Initial, not by the RTT value itself

D is wrong because the documents do not say RTT starts at a fixed value of 10; it is measured dynamically as round-trip delay

So the verified answer is: A.

The correct answers are A and B.

The Network Security Support Engineer 7.6 Study Guide states under OSPF Troubleshooting:

“Follow these steps to troubleshoot an OSPF problem between two peers:

Check that the local router can reach the remote peer. IP addresses must be in the same subnet and have the same subnet mask.

Ensure that IP protocol 89 is not blocked.

Hello and dead intervals must match.

The OSPF router ID for each peer must be unique. Duplicate router IDs are not allowed.

Do the MTUs match?

If authentication is enabled, the type and password must match on both sides.”**

The same page also summarizes the troubleshooting tips as:

“Do peers have an IP address within the same subnet?”

“Is IP protocol 89 blocked?”

This directly confirms:

A is correct

B is correct

Why the other options are wrong:

C is wrong because TCP port 179 is used by BGP, not OSPF. OSPF uses IP protocol 89, as the study guide explicitly notes

D is wrong because the study guide’s OSPF adjacency troubleshooting checklist does not require an active static route to the peer. OSPF neighbors form adjacency on directly reachable networks, and the guide instead focuses on same subnet, protocol 89, intervals, router ID, MTU, and authentication matching

So the verified answers are: A, B.

The correct answers are A and B. Security Fabric communication uses Fortinet-proprietary protocols, mainly FortiTelemetry and Neighbor Discovery. The study guide states that FortiTelemetry uses TCP port 8013, and that the connection is always established by the downstream FortiGate toward the upstream FortiGate. This validates option A. The same section also states that FortiTelemetry must be manually enabled. More precisely, the upstream FortiGate interface must have Security Fabric Connection enabled under administrative access so it can accept incoming Security Fabric connection requests. This validates option B.

Option C is wrong because only the FortiTelemetry TCP port 8013 can be changed; Neighbor Discovery uses UDP port 8014 and cannot be changed. Option D is also wrong because Security Fabric communication is not enabled automatically among all Fortinet devices. It requires the correct Security Fabric settings, interface administrative access, and downstream authorization. The study guide’s troubleshooting section confirms that when FortiTelemetry is disabled, the upstream FortiGate receives TCP 8013 SYN packets but does not complete the Security Fabric connection.

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 result is that the gateway address will not be updated, unless the existing gateway is no longer valid "

The study guide identifies preserve-session-route as the configuration responsible for this behavior.

Technical Explanation:

The exhibit shows two WAN interfaces, port1 and port2, with static default routes.

Originally, both interfaces participate in routing with equal priority. The administrator changes the priority of port2 to 20, making port1 the preferred interface for new route selections.

However, the existing sessions were established using port2, and its interface configuration includes:

config system interface

edit " port2 "

set preserve-session-route enable

next

end

Option A is correct: The preserve-session-route setting enables interface stickiness for sessions using port2.

Because the original gateway and route remain valid, FortiGate preserves the existing sessions ' routing information and continues forwarding them through port2.

Option B is correct: Increasing the priority value on port2 makes it less preferred than port1. Consequently, new sessions that use the relevant default route are directed through port1.

Why the other options are incorrect:

Option C: FortiGate does not automatically update existing SNAT session gateway information merely because a more preferred path becomes available. The guide identifies snat-route-change as a separate setting used to permit appropriate SNAT route updates.

Option D: A route change can cause affected sessions to be marked dirty and reevaluated, but it is not accurate to conclude that every session is necessarily marked dirty or that dirty status overrides interface stickiness.

Option E: SNAT session dirty-state handling does not depend exclusively on using an IP pool. Interface-based SNAT sessions can also be affected by routing changes.

Architectural Consideration:

This distinction is important for SD-WAN failback design. Preserving established sessions can help maintain connection continuity, but it can also prevent traffic from returning to a preferred WAN interface until the session ends or the preserved route becomes invalid.

The Enterprise Firewall 7.6 Administrator Study Guide specifically warns that all-zero phase 2 selectors can introduce invalid paths during migrations, particularly when many routes are advertised across VPN tunnels or overlapping networks exist. One recommended mitigation is to use dynamic routing protocols to explicitly control which subnets are permitted and advertised through the tunnel, making A correct.

Fortinet also recommends defining the required encryption domains precisely in the phase 2 selectors. Specifying the exact network segments ensures that only designated traffic is eligible for the IPsec tunnel, making D correct. An IPsec aggregate provides redundancy but does not solve inappropriate route or encryption-domain selection. Assigning IP addresses to tunnel interfaces can support routing designs, but it is not the documented mitigation for invalid paths caused by overly broad all-zero selectors.

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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.