Fortinet NSE4_FGT_AD-7.6 Exam Dumps - Actual Questions Answers

“The only security features you can apply using SSL certificate inspection mode are web filtering and application control... Note that while offering some level of security, certificate inspection does not allow FortiGate to inspect the flow of encrypted data.”

“To perform SSL inspection on traffic flowing through the FortiGate device, you must allow the traffic with a firewall policy and apply an SSL inspection profile to the policy... For antivirus or IPS control, you should use a deep-inspection profile.”

“When you use deep inspection, FortiGate impersonates the recipient of the originating SSL session, and then decrypts and inspects the content to find threats and block them. It then re-encrypts the content and sends it to the real recipient.”

Technical Deep Dive:

The exhibit shows that the policy is allowing HTTPS and the SSL/SSH inspection profile is certificate-inspection , not deep-inspection . That is the key issue. With certificate inspection, FortiGate can inspect only SSL metadata such as the certificate and SNI/hostname context; it cannot decrypt the HTTPS payload itself. Because EICAR is detected by antivirus through payload inspection, FortiGate must see the file contents. Without deep SSL inspection, the antivirus engine never gets the decrypted payload, so the file can pass even though the antivirus profile is attached.

Option A is incorrect because FortiGate firewall policies often use ACCEPT + security profile enforcement ; the session can still be blocked by antivirus after policy match. Option B is incorrect because web filter is not required for antivirus detection. Option C is incorrect because the real requirement is deep SSL inspection , not specifically proxy-based mode; full SSL inspection is the deciding factor here.

In practice, to block EICAR over HTTPS, you would apply a deep-inspection SSL profile to the policy, for example:

config firewall policy

edit < policy-id >

set inspection-mode flow

set av-profile " default "

set ssl-ssh-profile " deep-inspection "

next

end

On real hardware, this also matters for performance design. Simple firewall/NAT sessions are often NP fast-pathed, but once you enable deep SSL inspection and content scanning, traffic is typically handed to CPU/WAD/content-inspection path for decryption and scanning, so throughput is lower than certificate-inspection or no-inspection.

From the exhibits:

System performance output

Memory used: 90%

Free memory: ~5%

Default memory thresholds (FortiOS 7.6)

memory-use-threshold-green 82%

memory-use-threshold-red 88%

memory-use-threshold-extreme 89%

Because memory usage (90%) exceeds the extreme threshold (89%), the FortiGate enters conserve mode.

Effects of conserve mode (FortiOS 7.6 – verified)

B. FortiGate has entered conserve mode.

Correct

When memory usage exceeds the red/extreme threshold, FortiGate automatically enters conserve mode.

This is exactly the condition shown in the system performance output.

D. Administrators can change the configuration.

Correct

Even in conserve mode:

Administrators can still log in (GUI, SSH, console)

Configuration changes are allowed

FortiGate does not lock configuration access during conserve mode.

This behavior is explicitly documented in the FortiOS 7.6 Conserve Mode section.

Why the other options are incorrect

A. Administrators can access FortiGate only through the console port.

Incorrect

Network access (GUI/SSH) is still available in conserve mode unless otherwise restricted.

Console-only access is not a conserve-mode requirement.

C. FortiGate drops new sessions.

Incorrect (as a general statement)

FortiGate may drop or bypass new inspection-required sessions depending on fail-open/fail-close settings.

It does not universally drop all new sessions, so this statement is not always true.

According to the FortiOS 7.6 Study Guide and Parallel Path Processing documentation, flow-based antivirus inspection is designed to provide security with minimal impact on performance.

First, a defining characteristic of modern flow-based AV (specifically in its " hybrid " mode) is that FortiGate buffers the whole file but transmits to the client at the same time (Statement A). This behavior allows the client to start receiving data immediately to prevent session timeouts, while the FortiGate reassembles the file in memory to perform a signature check before the final packet is released.

Second, starting with recent FortiOS versions including 7.6, flow-based inspection uses a hybrid of the scanning modes (Statement B). Previously, flow mode offered " Quick " or " Full " scans; now, it combines these techniques to offer a balance between the speed of stream-based scanning and the thoroughness of archive inspection.

Third, the primary motivation for selecting this mode is that flow-based inspection optimizes performance compared to proxy-based inspection (Statement D). It processes traffic in a single pass using the IPS engine, avoiding the overhead associated with the WAD (proxy) process. Statement C is incorrect because if a virus is detected, the last packet is withheld and the connection is reset to prevent the file from being completed. Statement E is less accurate as the IPS engine loads the AV engine to perform the task rather than acting as a " standalone " entity in the context of file scanning.