A closely related routing principle from the guide is:

“For each session, FortiGate performs two route lookups... After completing these two lookups, FortiGate writes the routing information to its session table. Subsequent packets are routed according to the session table, not the routing table.”

Also, the guide notes an HA limitation that helps explain the same design principle for FortiGate-terminated sessions:

“Enabling session pickup allows active sessions to be seamlessly handed picked up by the new primary in the event of an HA failover... Note that there are some limitations to this – for example, any sessions that terminate at the FortiGate itself ( e.g. SSL VPN, proxy sessions ) cannot be handed off to another FortiGate and must be restarted on the new primary.”

Technical Deep Dive:

The correct answer is D .

In multi-WAN environments, session preservation is used so that traffic for sessions that are tightly bound to the FortiGate interface they terminate on—most notably SSL VPN and other FortiGate-terminated flows—does not suddenly switch to another egress interface just because the routing table changes. Those sessions are sensitive to interface consistency. If replies start leaving through a different WAN after a route recalculation, the remote peer may see an address/interface mismatch and the session can break.

That means:

A is the opposite of session preservation. Preservation is meant to avoid moving active sessions around.

B is not the purpose of the feature.

C is unrelated.

D correctly describes why an administrator would enable it.

Operationally, this matters most for SSL VPN , management-plane flows, and other sessions that terminate on the FortiGate itself , not just ordinary transit traffic. Transit sessions are generally tracked in the session table and can often survive normal routing behavior more gracefully, but FortiGate-terminated sessions are much more sensitive to WAN/interface changes.

“When you enable reliable logging on FortiGate, the log transport delivery method changes from UDP to TCP. TCP provides reliable data transfer, guaranteeing that the transferred data remains intact and arrives in the same order in which it was sent.”

“Optionally, if using reliable logging, you can encrypt communications using SSL-encrypted OFTP traffic, so when a log message is generated, it is safely transmitted across an unsecured network.”

Technical Deep Dive:

The correct answer is C . The study guide explicitly ties reliable logging to TCP transport and optionally to SSL-encrypted OFTP . Among the choices, the padlock icon is the only one that meaningfully indicates secure, reliable log transport behavior. A green check icon usually indicates that the FortiGate–FortiAnalyzer connection is simply up , not specifically that reliable logging is enabled. Interface status being up is unrelated, and real-time logging mode describes delivery behavior, not the reliable transport indicator itself.

So, exam-wise, the best answer is C .

From the CLI perspective, reliable logging changes the transport from UDP to TCP, and with encryption enabled it uses SSL-protected OFTP. That is why the GUI indicator associated with secure transport is the most relevant visual clue here.

In FortiOS 7.6 Application Control, security logs are generated primarily for actions such as Block or Monitor, not for Allow actions.

What is happening in the exhibit

An Application Override is configured for ABC.Com

Type: Application

Action: Allow

The application control profile is applied to a firewall policy

Logging is enabled on the firewall policy

Traffic to ABC.Com is successfully allowed

However, no security logs appear for ABC.Com.

Why no logs are generated

In FortiOS 7.6:

Application Control logs are written to Security Logs when:

An application is Blocked

An application is Monitored

When an application action is set to Allow:

The traffic is permitted silently

No application control security log is generated

Even if policy logging is enabled

This is expected and documented behavior.

To generate logs for allowed applications, the action must be set to Monitor, not Allow.

Why the other options are incorrect

A. ABC.Com is hitting the category Excessive-BandwidthIncorrect. ABC.Com has a higher-priority explicit override (priority 1), so it is not evaluated against the Excessive-Bandwidth filter.

B. The ABC.Com Type is set as Application instead of FilterIncorrect. Application-type overrides are valid and commonly used; this does not suppress logging.

C. The ABC.Com must be configured as a web filter profileIncorrect. This traffic is being evaluated by Application Control, not Web Filter.