NSE4 Practice Questions 2 — 50 Questions

Question 1

An administrator wants to implement ZTNA (Zero Trust Network Access) on a FortiGate to secure access to an internal application. Which TWO components are essential for a ZTNA configuration?

Accepted Answer

A proxy-based firewall policy. ZTNA on FortiGate requires a proxy-based firewall policy to intercept and inspect application-layer traffic. This policy type enables the FortiGate to act as a reverse proxy, terminating TLS connections and enforcing access control based on user identity and device posture before forwarding traffic to the internal application.

Answer

A firewall policy using IPsec VPN

Answer

A FortiGate in transparent mode

Answer

A policy-based IPsec tunnel

Question 2

What is the primary difference between route-based and policy-based IPsec VPNs on a FortiGate?

Accepted Answer

Route-based uses a tunnel interface, policy-based uses firewall policies to define traffic selectors.. The primary difference is that route-based IPsec VPNs use a tunnel interface (e.g., 'phase1-interface' and 'phase2-interface') which participates in routing, while policy-based IPsec VPNs rely on firewall policies with explicit traffic selectors (source/destination addresses and services) to trigger encryption. In route-based VPNs, the tunnel interface is assigned an IP address and routes are used to direct traffic into the tunnel, decoupling encryption from policy matching. In policy-based VPNs, the firewall policy itself defines what traffic is encrypted, making the traffic selector part of the policy configuration.

Answer

Route-based requires a static route, policy-based uses dynamic routing.

Answer

Route-based encrypts all traffic, policy-based encrypts only specified services.

Answer

Route-based supports only IKEv2, policy-based supports both IKEv1 and IKEv2.

Question 3

Which of the following best describes the purpose of a captive portal on a FortiGate?

Accepted Answer

To authenticate users before granting network access. A captive portal on a FortiGate intercepts HTTP/HTTPS traffic from unauthenticated users and redirects them to a web-based login page. Once the user provides valid credentials (e.g., via local database, LDAP, or RADIUS), the FortiGate creates an authenticated session, allowing network access. This is a core mechanism for guest Wi-Fi or BYOD onboarding, not for remote access or encryption.

Answer

To provide secure remote access to internal resources

Answer

To encrypt traffic between sites

Answer

To block malware from entering the network

Question 4

A FortiGate administrator is configuring a policy-based routing (PBR) rule to send all traffic from the 'Engineering' VLAN (10.1.0.0/16) to a dedicated internet link through gateway 203.0.113.1. The administrator also wants to apply a traffic shaper to limit bandwidth. Which THREE configuration tasks must be performed?

Accepted Answer

Define a traffic shaper object with the desired bandwidth limits. A traffic shaper object must first be defined with the desired bandwidth limits (e.g., maximum rate, burst size) before it can be applied to a firewall policy. Without this object, the shaper cannot be referenced or enforced.

Answer

Enable SD-WAN on the FortiGate

Answer

Configure Central NAT to translate the source IP

Question 5

An administrator wants to restrict SSL VPN access to only users who have a valid client certificate issued by the company's internal CA. Which setting should be configured?

Accepted Answer

Enable 'require client certificate' in the SSL VPN settings. The 'require client certificate' setting in the SSL VPN portal or interface configuration enforces mutual TLS (mTLS), where the FortiGate requests and validates a client certificate against the configured CA. This ensures that only users presenting a valid certificate issued by the company's internal CA can establish the SSL VPN tunnel, regardless of their authentication credentials.

Answer

Configure a firewall policy with identity-based authentication

Answer

Enable 'certificate-based authentication' in the user group

Answer

Import the users' public keys into the FortiGate

Question 6

An admin is troubleshooting why traffic from a specific host (10.0.1.10) to a web server (203.0.113.50:80) is being denied. The FortiGate has several policies. Which TWO CLI commands should the admin use to identify which policy is matching the traffic? (Choose two.)

Accepted Answer

diagnose firewall iprope lookup 10.0.1.10 -> 203.0.113.50 80. B is correct because 'diagnose firewall iprope lookup' is the exact CLI command that performs a simulated policy lookup for a given source IP, destination IP, and port, showing which firewall policy matches the traffic. This allows the admin to verify the policy match without generating real traffic.

Answer

execute ping 203.0.113.50

Answer

diagnose debug flow

Answer

get firewall policy

Question 7

An administrator has configured an IPS sensor to block critical-severity attacks. However, after a week, they notice that a known exploit (CVE-2021-44228) is still getting through. Which configuration change should be made to improve detection?

Accepted Answer

Enable the specific IPS signature for the exploit in the sensor.. The IPS sensor must have the specific signature for CVE-2021-44228 (Log4Shell) enabled to detect and block it. Even if the sensor is set to block critical-severity attacks, the signature for this exploit may be disabled by default in the sensor's signature database. Enabling the specific signature ensures the sensor inspects traffic for the exploit's unique patterns and applies the configured action.

Answer

Set the IPS sensor severity filter to 'low' and above.

Answer

Change the IPS sensor action from 'default' to 'block' for all signatures.

Answer

Create a custom IPS signature for the exploit.

Question 8

A company is deploying a FortiGate HA cluster in active-passive mode across two data centers. The network team reports that after a failover, some existing TCP sessions are dropped. Which configuration change should be applied to maintain session persistence during failover?

Accepted Answer

Enable session synchronization between cluster members. In an active-passive HA cluster, session synchronization (config.sys ha session-sync) ensures that TCP session state information is replicated from the active unit to the passive unit. Without this, the passive unit has no knowledge of existing sessions after a failover, causing them to be dropped. Enabling session synchronization allows the new active unit to continue forwarding traffic for established sessions seamlessly.

Answer

Disable NAT inspection on the firewall policy

Answer

Configure gratuitous ARP on the virtual IP

Answer

Increase the heartbeat interval to 2 seconds

Question 9

A FortiGate administrator is troubleshooting why traffic from a specific internal host is not being allowed through a firewall policy. The policy appears correct and is enabled. Which TWO diagnostic commands could the administrator use to determine if the traffic is matching a different policy?

Accepted Answer

diagnose firewall iprope list. The 'diagnose firewall iprope list' command (D) displays the kernel's internal firewall rule list, allowing the administrator to verify the exact order and matching criteria of all policies. The 'diagnose debug flow' command (E) enables real-time packet flow tracing, showing which policy each packet matches and why it is accepted or denied. Together, these two commands directly reveal if traffic is matching a different policy than intended.

Answer

get system performance status

Answer

config system ha

Answer

execute ping options

Question 10

What is the difference between certificate inspection and full SSL deep inspection on a FortiGate?

Accepted Answer

Certificate inspection only validates the server certificate; deep inspection decrypts and inspects the content. Certificate inspection only validates the server certificate's authenticity and checks for revocation, but does not decrypt the traffic payload. Full SSL deep inspection (also called SSL inspection) decrypts the entire SSL/TLS session, allowing the FortiGate to inspect the content for threats like malware, data leaks, or policy violations. This is why option B is correct: certificate inspection validates the certificate, while deep inspection decrypts and inspects the content.

Answer

Certificate inspection decrypts traffic; deep inspection does not

Answer

Deep inspection is faster than certificate inspection

Answer

Both provide the same level of security

Question 11

Which statement best describes the implicit deny policy at the end of a FortiGate policy list?

Accepted Answer

It is always present and denies any traffic that does not match an explicit allow policy. The implicit deny policy is a built-in, last-resort rule at the bottom of the FortiGate policy list that silently drops any traffic not matching an explicit allow policy. It cannot be moved, disabled, or deleted because it is a fundamental security mechanism ensuring that only explicitly permitted traffic is allowed through the firewall.

Answer

It denies all traffic that does not match any explicit policy, and it logs the denied traffic

Answer

It can be moved to a different position in the policy list

Answer

It can be disabled or deleted by the admin

Question 12

An administrator configures a web filter profile with FortiGuard category blocking and URL filter to allow example.com. Users report that example.com is still blocked. What is the most likely cause?

Accepted Answer

The FortiGuard category action is set to 'block' and takes precedence over the URL filter allow rule. When both FortiGuard category blocking and a URL filter are configured in the same web filter profile, the FortiGuard category action (e.g., 'block') is evaluated first and takes precedence over any URL filter allow rule. This is because FortiGate processes web filter rules in a specific order: FortiGuard category blocking is applied before URL filter entries. Therefore, even if a URL filter explicitly allows example.com, the FortiGuard category block will prevent access.

Answer

The URL filter requires deep inspection to be enabled

Answer

The URL filter entry is placed after the FortiGuard category in the policy

Answer

The DNS filter is blocking example.com before the web filter is evaluated

Question 13

A network administrator creates a firewall policy allowing HTTP traffic from the internal network to a web server in the DMZ. Users report that they cannot access the web server. The administrator runs 'diagnose firewall iprope list' and sees the policy is present. What is the MOST likely cause of the issue?

Accepted Answer

A deny policy with a lower policy ID is matching the traffic before the allow policy. The 'diagnose firewall iprope list' command confirms the allow policy exists in the FortiGate's kernel policy list, meaning it is present and enabled. However, FortiGate evaluates policies in sequential order based on policy ID (lowest first), so a deny policy with a lower ID that matches the same traffic (e.g., from internal to DMZ) will be hit first, blocking the HTTP request before the allow policy can be evaluated. This is the most likely cause because the policy is present but not being matched due to ordering.

Answer

The firewall policy has an incorrect source interface

Answer

The policy is disabled

Answer

The web server is not responding to HTTP requests

Question 14

A FortiGate administrator is configuring ZTNA to secure access to an internal application. The administrator creates a ZTNA access proxy and a ZTNA rule. However, users connecting from the internet receive a 403 Forbidden error. The administrator verifies that the users are authenticated and the application is reachable. What is the MOST likely cause?

Accepted Answer

The ZTNA rule requires a specific client posture tag that the users' devices do not have. The 403 Forbidden error in ZTNA typically indicates that the client device does not meet the required security posture. Even though users are authenticated and the application is reachable, the ZTNA rule enforces a specific client posture tag (e.g., antivirus enabled, OS patch level) via FortiClient telemetry. If the device lacks the required tag, FortiGate denies access with a 403, as the ZTNA access proxy validates both identity and device compliance before proxying traffic.

Answer

The firewall policy allowing traffic to the application is placed after a deny-all policy

Answer

The application's IP address is not included in the ZTNA access proxy's destination

Answer

The ZTNA access proxy does not have a valid SSL certificate

Question 15

An admin is configuring a policy-based NAT (central SNAT) to translate internal users to a pool of public IPs using overload. The admin wants to ensure that specific applications using non-standard ports are not affected by NAT. Which THREE steps should the admin consider?

Accepted Answer

Disable NAT for those applications by adding a policy before the NAT policy with 'set nat disable'. Adding a policy before the central SNAT policy with `set nat disable` explicitly exempts specific traffic from NAT translation, ensuring that applications using non-standard ports are not affected by the overload behavior. Option B is correct because configuring a separate IP pool dedicated to those applications allows you to control the NAT behavior independently, such as using a pool without PAT or with a fixed port range, thereby avoiding port remapping issues. Option C is correct because using a fixed port range in the IP pool confines source port allocation to a specified range, accommodating applications that expect particular ports. Option D is incorrect because a VIP is for destination NAT, not source NAT, and does not address source port modification. Option E is incorrect because enabling NAT on the policy would translate all traffic, not protect specific applications.

Answer

Use central SNAT with a VIP for source NAT

Answer

Enable 'set nat enable' on the policy

Question 16

A FortiGate administrator needs to create a firewall policy that allows traffic from the internal network (10.0.0.0/8) to a public web server (203.0.113.10) on port 443. The policy must also perform source NAT using the FortiGate's external IP (198.51.100.1). Which NAT configuration should be applied?

Accepted Answer

Enable NAT on the firewall policy without specifying an IP pool. When a firewall policy uses source NAT (SNAT) to translate internal source IPs to the FortiGate's own egress interface IP, simply enabling NAT on the policy without specifying an IP pool is sufficient. This is the default behavior: the FortiGate automatically performs source NAT using the IP address of the outgoing interface (in this case, 198.51.100.1). No additional IP pool or central NAT rule is required for this standard outbound NAT scenario.

Answer

Create an IP pool with the external IP and reference it in the firewall policy

Answer

Create a VIP for the web server and reference it in the firewall policy

Answer

Configure Central SNAT and a matching rule

Question 17

A company uses FortiGate with firewall policies to control access between internal VLANs. Users in VLAN 10 report they can access internet but cannot reach a server in VLAN 20 on port 443. The server is reachable from other VLANs. The administrator checks the firewall policy configuration: there is a policy from VLAN10 to VLAN20 allowing HTTPS, with NAT disabled and logging enabled. The policy has a schedule set to 'Always'. The administrator also checks that there are no overlapping policies. What is the most likely cause?

Accepted Answer

A security profile applied to the policy is blocking the HTTPS traffic.. Security profiles (such as web filtering, application control, or SSL inspection) applied to a firewall policy can inspect and block HTTPS traffic even when the policy itself allows the service. Since the server is reachable from other VLANs and the policy explicitly permits HTTPS with NAT disabled and logging enabled, the most likely cause is that a security profile is dropping or denying the traffic.

Answer

NAT is disabled, so the server cannot send replies back.

Answer

The policy order is incorrect; a deny policy above is blocking traffic.

Answer

The schedule is configured incorrectly and the policy is inactive during the current time.

Question 18

A FortiGate admin is configuring a hub-and-spoke IPsec VPN. The hub has multiple phase 2 configurations for each spoke. The spokes can communicate with the hub but not with each other. The admin wants to allow spoke-to-spoke traffic through the hub. Which configuration change is required on the hub?

Accepted Answer

Modify the Phase 2 selectors on the hub to include both spoke subnets and add firewall policies allowing traffic between the spoke networks. In a hub-and-spoke VPN with policy-based IPsec, the hub's Phase 2 selectors define which subnets can communicate through each tunnel. By default, each spoke's Phase 2 selector only includes the hub and that specific spoke's subnets, blocking spoke-to-spoke traffic. Adding both spoke subnets to the hub's Phase 2 selectors and creating firewall policies that permit traffic between those spoke networks allows the hub to route traffic between spokes, effectively enabling spoke-to-spoke communication through the hub.

Answer

Change the IPsec mode from policy-based to route-based

Answer

Enable 'add-route' on the hub's Phase 1 settings

Answer

Configure a static route on each spoke pointing to the other spoke's subnet via the tunnel

Question 19

A network administrator is configuring a new FortiGate and needs to ensure that all traffic from the internal network to the internet is source NATed to the public IP address on port1. The default route points to port1. Which configuration step is required to achieve this?

Accepted Answer

Enable NAT on the firewall policy from internal to internet. Source NAT (SNAT) on a FortiGate is configured at the firewall policy level, not on the interface or via a static route. By enabling NAT on the firewall policy from the internal network to the internet, the FortiGate automatically translates the source IP of traffic egressing port1 to the interface's primary IP address (the public IP). This is the standard method for implementing source NAT in FortiOS, as defined in the FortiGate Administration Guide.

Answer

Configure a static route to the internet with NAT enabled

Answer

Set the interface port1 to NAT mode in its settings

Answer

Create an IP pool with the public IP and reference it in the policy

Question 20

A network administrator wants to prevent users from downloading files with .exe extensions via HTTP and HTTPS. Which security profile feature should be used?

Accepted Answer

Antivirus profile with 'block' action for file pattern matching .exe. The Antivirus profile in FortiGate can be configured with a file pattern matching rule to block files based on their extension, such as .exe. This feature operates at the application layer, inspecting HTTP and HTTPS traffic (via SSL inspection) to identify and block executable files before they reach the user. Option C is correct because it directly uses the antivirus engine's file pattern matching capability to enforce this policy.

Answer

Web filter profile with URL filter to block .exe sites

Answer

Application control profile to block file transfer applications

Answer

IPS profile to block executable file transfers