NSE4_FGT_AD-7.6 Exam Dumps - Fortinet NSE 4 - FortiOS 7.6 Administrator

According to the FortiOS 7.6 Administration Guide and Fortinet hardware acceleration (NTurbo) documentation, the correct answer is A.

What NTurbo Is (FortiOS 7.6 – Verified)

NTurbo is a hardware-based acceleration feature available on specific FortiGate models. It is designed to improve antivirus and IPS performance when operating in flow-based inspection mode.

NTurbo works by creating a fast, optimized data path between:

FortiGate ingress interface

IPS/AV engine

FortiGate egress interface

This minimizes CPU involvement and reduces packet traversal overhead.

Why Option A Is Correct

A. For flow-based inspection, NTurbo establishes a dedicated data path to redirect traffic between the IPS engine and FortiGate ingress and egress interfaces.

This is exactly how NTurbo works, as documented:

NTurbo applies to flow-based inspection only

It accelerates IPS and antivirus scanning

It creates a dedicated fast path that bypasses unnecessary processing steps

This significantly improves throughput and lowers latency

This description matches Fortinet’s official explanation of NTurbo.

Why the Other Options Are Incorrect

B. NTurbo creates two inspection sessions

Incorrect. NTurbo does not duplicate sessions; it optimizes the packet path.

C. NTurbo offloads traffic to the content processor (proxy-based)

Incorrect. NTurbo does not apply to proxy-based inspection and does not offload to content processors.

D. NTurbo buffers the whole file and then sends it to the antivirus engine

Incorrect. Buffering entire files is a proxy-based behavior, not NTurbo.

Based on the FortiOS 7.6 Infrastructure and IPsec VPN documentation, Dead Peer Detection (DPD) can be configured in three primary modes: On Demand, On Idle, and Disabled.

On Demand (Default Mode): This mode is specifically designed to minimize unnecessary traffic. In this mode, FortiGate sends DPD probes only when there is no inbound traffic but the FortiGate is attempting to send outbound traffic. Because network communication is typically bidirectional, the absence of inbound traffic while outbound traffic is being sent is a primary indicator of a potentially dead tunnel. This matches the specific requirement described in the question.

On Idle: In this mode, DPD probes are sent if no traffic (neither inbound nor outbound) has been observed in the tunnel for a specific period. It verifies the tunnel status even when the connection is completely idle.

Enabled: In older versions or specific CLI contexts, "Enabled" may refer to periodic DPD, but in the current FortiOS 7.x/7.6 GUI and CLI terminology for Phase 1 settings, the active modes are defined as on-demand or on-idle.

Disabled: In this mode, the FortiGate does not send DPD probes but will still respond to DPD probes sent by the remote peer.

The requirement that the administrator wants probes sent only when there is no inbound traffic (usually implying the FortiGate is sending but not receiving) is the fundamental definition of the On Demand mechanism in the Fortinet curriculum.

Based on the exhibit and the FortiOS 7.6 SSL/SSH Inspection documentation, the correct answer is C.

Understanding the Exhibit Configuration

In the SSL/SSH Inspection Profile, the following settings are shown:

Inspection method: Full SSL Inspection

Server certificate SNI check: Strict

This setting directly controls how FortiGate validates the Server Name Indication (SNI) provided by the client during the TLS handshake.

FortiOS 7.6 Behavior of “Server certificate SNI check”

FortiOS supports three modes for Server certificate SNI check:

Disable

No validation between SNI and server certificate.

Enable

FortiGate checks SNI against the certificate.

If mismatch occurs, FortiGate may still allow the session with reduced validation.

Strict

FortiGate enforces a strict match.

The SNI must match either the CN (Common Name) or one of the SAN (Subject Alternative Name) entries in the server certificate.

If the SNI does not match either CN or SAN, the TLS session is immediately terminated.

The exhibit clearly shows Strict selected.

Why Option C is Correct

With Strict enabled, FortiGate rejects the TLS connection when:

The SNI does not match the CN, and

The SNI does not match any SAN entry

This results in the connection being closed, not allowed with warnings or fallback behavior.

Therefore:

C. FortiGate will close the connection if the SNI does not match the CN or SAN fields is exactly the documented behavior.

Why the Other Options Are Incorrect

A: FortiGate does not fall back to using the CN for URL filtering when Strict is enabled.

B: There is no “accept with warning” behavior in Strict mode.

D: Incorrect logical condition. FortiGate does not require mismatch with both CN and SAN simultaneously; a mismatch with either valid field set is sufficient to close the connection.

"Also, advanced mode supports nested or inherited groups; that is, users can be members of subgroups that belong to monitored parent groups." "In advanced mode, you can configure FortiGate as an LDAP client and configure the group filters on FortiGate. You can also configure group filters on the collector agent."

Collector Agent Advanced Mode provides deeper integration between FortiGate, LDAP, and Active Directory, compared to standard mode.

Key features of Collector Agent Advanced Mode

B. FortiGate can be configured as an LDAP client and group filters can be configured on FortiGate.

Correct

In advanced mode:

FortiGate directly queries LDAP/AD

User group filters are configured on FortiGate, not only on the Collector Agent

This allows more flexible and scalable user/group-based policies

D. Advanced mode supports nested or inherited groups.

Correct

Advanced mode supports:

Nested AD groups

Inherited group memberships

This is one of the primary reasons advanced mode is used in complex AD environments

Why the other options are incorrect

A. Security profiles only to user groups

Incorrect.

Security profiles can be applied to users or groups, depending on policy configuration.

C. Uses NetBIOS Domain\Username format

Incorrect.

NetBIOS naming is associated with standard mode

Advanced mode typically uses LDAP DN-based identification

From the exhibits:

The firewall policy has Application Control enabled and uses certificate-inspection for SSL inspection.

The application sensor has Application and Filter Overrides with the following order (priority):

Excessive-Bandwidth with action Block

Google (vendor filter) with action Monitor

In FortiOS, Application and Filter Overrides are evaluated by priority (top-down). The first matching override is applied. If traffic matches an earlier override with Block, it will be blocked even if a later override would Monitor/Allow it.

Why Google apps fail while www.fortinet.com works:

Many Google applications can be detected as (or can trigger) the Excessive-Bandwidth behavior/signature depending on the specific service and traffic pattern.

Because Excessive-Bandwidth (Block) is above Google (Monitor), Google-related traffic may match the first rule and be blocked before the Google override is evaluated.

Access to www.fortinet.com works because that traffic is not matching the Excessive-Bandwidth override.

Therefore, to resolve:

B. Move up Google in the Application and Filter Overrides section to set its priority higher

This ensures Google matches the Google override before any broader blocking override is applied.

E. Set the action for Google in the Application and Filter Overrides section to Allow

This explicitly permits Google applications once the higher-priority match occurs (stronger than Monitor for troubleshooting and ensuring access).

Why the other options are not the best fit here:

A (deep-content inspection) can help identify more HTTPS applications, but the exhibit already shows a specific Google override configured; the immediate issue is the override evaluation order and action.

C relates to Web Filter URL categories, but the problem is occurring under Application Control behavior/vendor overrides.

D (flow-based) is not required to fix an override priority/action conflict.