Fortinet NSE4_FGT_AD-7.6 Dumps Questions Answers

In FortiOS 7.6, when a FortiGate is operating in NAT mode, physical interfaces that participate in traffic forwarding (such as LAN and DMZ) must meet certain fundamental requirements.

Correct statements

D. Both interfaces must have IP addresses assigned.

Correct

In NAT mode, FortiGate operates as a Layer-3 device.

Every interface that forwards traffic must have an IP address.

Without an IP address:

The interface cannot participate in routing

Firewall policies cannot be applied correctly

This is a mandatory requirement.

C. Both interfaces must have directly connected routes on the routing table.

Correct

When an IP address is assigned to an interface, FortiGate automatically installs a connected route for that subnet in the routing table.

These connected routes are required so FortiGate:

Knows how to reach the locally attached networks

Can forward traffic between LAN and DMZ

While administrators do not manually create these routes, their presence is required for correct operation.

Why the other options are incorrect

A. Both interfaces must have DHCP enabled and roles assigned.

Incorrect

DHCP is optional; interfaces can use static IPs.

Interface roles (LAN, DMZ, WAN) are administrative/GUI aids, not functional requirements.

B. Both interfaces must have the interface role assigned.

Incorrect

Interface roles affect GUI grouping and some default behavior.

They are not required for NAT mode operation or traffic forwarding.

“You may need to exempt traffic from SSL inspection if it is causing problems with traffic, or for legal reasons.”

“Performing SSL inspection on a site that is enabled with HTTP Strict Transport Security (HSTS), for example, can cause problems with traffic. Remember, the only way for FortiGate to inspect encrypted traffic is to intercept the certificate coming from the server and generate a temporary one. After FortiGate presents the temporary SSL certificate, browsers that use HSTS refuse to proceed.”

“Laws protecting privacy might be another reason to bypass SSL inspection. For example, in some countries, it is illegal to inspect SSL bank-related traffic. Configuring an exemption for sites is simpler than setting up firewall policies for each individual bank. You can exempt sites based on their web category, such as Finance and Banking...”

“The predefined deep-inspection and custom-deep-inspection profiles exclude some web categories—Finance and Banking, and Health and Wellness—and some FQDN addresses...”

Technical Deep Dive:

The correct answers are B and D .

B is correct because the study guide explicitly says SSL inspection may be bypassed for legal reasons , especially where privacy laws restrict inspection of sensitive categories such as Finance and Banking . The same privacy rationale also explains why Health and Wellness is commonly exempted.

D is correct because some sites break under deep inspection due to HSTS . FortiGate must generate and present a temporary certificate during full SSL inspection, and browsers enforcing HSTS can reject that interception flow. That is why some sites are exempted from deep inspection.

Why the others are wrong:

A is not stated in the guide.

C refers to the separate Reputable websites option, which is a FortiGuard-maintained allowlist feature, not the reason the predefined categories shown in the exhibit are excluded.

From an operational standpoint, this is a classic balance between security visibility and application/legal compatibility . Deep inspection gives FortiGate payload visibility, but it can interfere with pinned-certificate/HSTS behavior and can violate privacy policy for regulated content.

From the exhibits:

The Application Control sensor has these key settings:

Application and Filter Overrides

Priority 1: Excessive-Bandwidth (Type: Filter) with Action Block

Priority 2: Google (Type: Filter) with Action Monitor

Category actions shown include Social Media set to Block (this category includes Facebook).

The firewall policy is using:

Flow-based inspection

Application control enabled (profile: default)

Deep inspection enabled (helps identify applications inside HTTPS)

Logging enabled

FortiOS applies Application Control as follows (top-down within the Application Control profile):

Overrides are evaluated by priority (highest priority first).

The first matching override determines the action (block/monitor/allow) for that traffic.

Category-based actions apply to applications that fall into those categories unless an override matches first.

Why A is correct

A. YouTube access is blocked based on Excessive-Bandwidth Application and Filter override settings.

The profile explicitly blocks the Excessive-Bandwidth behavior filter at the highest override priority.

When YouTube traffic is detected as matching the Excessive-Bandwidth behavior, FortiGate will apply the Block action due to the override.

Because this is a priority override, it is enforced before lower-priority entries.

Why B is correct

B. Facebook access is blocked based on the category filter settings.

The Application Sensor shows Social Media configured with a Block action.

Facebook is categorized under Social Media, so it will be blocked when matched by Application Control.

Why C is not correct

C. Facebook access is allowed but you cannot play Facebook videos...

Since the Social Media category is set to Block, Facebook would be blocked at the category level (not merely video playback).

Why D is not correct

D. YouTube search is allowed based on the Google override...

The Google override action is Monitor, not Allow.

“Monitor” logs/detects but does not override a block condition to “allow” traffic.

Also, YouTube traffic is not guaranteed to be treated as “Google” in a way that would permit it, and any matching block condition (such as Excessive-Bandwidth) would still take precedence.