NSE4 Practice Test 2 — 10 Questions

Question 1

What is the purpose of the 'safe search' option in a FortiGate web filter profile?

Accepted Answer

It filters explicit content from search engine results. The 'safe search' option in a FortiGate web filter profile forces supported search engines (such as Google, Bing, and Yahoo) to filter explicit content from search results. This is achieved by appending specific parameters to the search engine URLs (e.g., &safe=active for Google), ensuring that adult or offensive material is suppressed regardless of the user's individual search settings.

Answer

It enforces the use of HTTPS for search engines

Answer

It allows users to bypass URL filters during safe search

Answer

It blocks all search engine traffic

Question 2

Which THREE conditions must be met for a firewall policy with FSSO authentication to work correctly?

Accepted Answer

The FortiGate must be able to communicate with the domain controller. FSSO (Fortinet Single Sign-On) relies on the FortiGate communicating with the domain controller to retrieve user login events via NetAPI or WMI. Without this communication, the FortiGate cannot map user identities to IP addresses, which is essential for FSSO-based authentication in firewall policies.

Answer

The user's IP address must be in the destination address range of the policy

Answer

The user must be authenticated to the FortiGate locally

Question 3

A FortiGate administrator is troubleshooting a dial-up IPsec VPN where remote users can connect but traffic does not pass. The Phase 1 and Phase 2 status show 'up'. The administrator runs 'diagnose vpn tunnel list' and sees the tunnel is up. However, 'diagnose sys session list' shows no sessions for the remote user's IP. What is the MOST likely cause?

Accepted Answer

There is no firewall policy permitting traffic from the dial-up interface to the destination network. Even when Phase 1 and Phase 2 are up and the tunnel is established, traffic will not pass through a dial-up IPsec VPN unless a firewall policy explicitly permits traffic from the dial-up interface (often the virtual IPsec interface) to the destination network. The 'diagnose sys session list' showing no sessions for the remote user's IP confirms that the FortiGate is not processing any traffic for that user, which points to a missing or misconfigured firewall policy rather than an encryption or routing issue.

Answer

The Phase 2 proposal uses AES256 but the remote client only supports AES128

Answer

The FortiGate's routing table does not have a route to the remote user's subnet

Answer

The remote user's FortiClient is blocking split tunneling

Question 4

A network administrator notices that HTTP traffic to a specific website is being blocked by the web filter profile, but the website is categorized as 'General – Personal' in FortiGuard, which is allowed. What could cause this block?

Accepted Answer

A URL filter entry is blocking the specific website. A URL filter entry can explicitly block a specific website regardless of its FortiGuard category. Even if the category 'General – Personal' is allowed in the web filter profile, a more specific URL filter rule with a higher priority (lower order number) can override the category-based action. This is a common scenario where an administrator creates a custom URL block for a particular domain or URL pattern, which takes precedence over the FortiGuard category lookup.

Answer

The web filter profile has an incorrect FortiGuard category override

Answer

The antivirus profile is blocking the website

Answer

DNS filter is blocking the domain

Question 5

An administrator configures an aggregate interface (port1 and port2) on a FortiGate. After connecting the switch ports, the aggregate interface shows 'down'. The individual member ports are up. What is the MOST likely cause?

Accepted Answer

The switch ports are not configured for LACP or static aggregation. The aggregate interface remains down because the switch ports are not configured for LACP or static aggregation. For a FortiGate aggregate interface to come up, both the FortiGate member ports and the corresponding switch ports must be configured with the same aggregation protocol (LACP active/passive or static). Without this, the switch treats the ports as individual links, causing a mismatch that keeps the aggregate interface down.

Answer

The member ports are set to different speeds

Answer

The aggregate interface IP address is in the same subnet as the management interface

Answer

The FortiGate needs a reboot after creating an aggregate interface

Question 6

A network administrator has configured a firewall policy allowing traffic from the internal network (10.0.0.0/8) to the internet. Users report that some websites are not loading. The administrator runs 'diagnose firewall iprope list 100000' and sees the policy listed with a hit count of zero. What is the MOST likely cause?

Accepted Answer

The policy is placed below a more specific or broader policy that matches the same traffic. A hit count of zero indicates the firewall policy has never matched any traffic. When a more specific or broader policy exists above it in the sequence, the FortiGate processes policies top-down and stops at the first match, so the lower policy never gets evaluated. This is the most likely cause given that the policy is present but unused.

Answer

The source interface or destination interface is incorrectly configured

Answer

The policy has a schedule that does not match the current time

Answer

The FortiGate has a routing issue preventing traffic from reaching the internet

Question 7

A FortiGate is configured for SSL deep inspection using a CA certificate. Users report that some websites show certificate errors. The administrator wants to allow these sites without inspection. Which setting should be used?

Accepted Answer

Add the websites to the SSL/SSH exemption list. The SSL/SSH exemption list allows administrators to specify websites that should bypass SSL deep inspection entirely, preventing certificate errors for sites that use self-signed, expired, or otherwise untrusted certificates. This is the intended mechanism in FortiOS to exclude specific destinations from inspection while maintaining inspection for all other traffic.

Answer

Disable certificate validation in the SSL inspection profile

Answer

Create a separate firewall policy without SSL inspection

Answer

Set the action for invalid certificates to 'allow'

Question 8

A FortiGate configured with IPS anomaly detection is generating false positives for the 'tcp_syn_flood' anomaly. The administrator wants to reduce the false positives without completely disabling the detection. Which action should the administrator take?

Accepted Answer

Increase the threshold value. Increasing the threshold value reduces false positives by requiring a higher rate of TCP SYN packets per second before the 'tcp_syn_flood' anomaly triggers an alert or action. This allows legitimate traffic bursts to pass without being flagged, while still detecting genuine SYN flood attacks. The threshold defines the sensitivity of the anomaly detection; raising it makes the detection less sensitive to low-volume spikes.

Answer

Disable the anomaly and use a custom IPS signature

Answer

Decrease the threshold value

Answer

Set the action to 'pass'

Question 9

Which THREE factors should be considered when tuning IPS to reduce false positives?

Accepted Answer

Excluding trusted source IP addresses from certain signatures.. Excluding trusted source IP addresses from certain signatures prevents the IPS from generating alerts for traffic that is known to be legitimate, directly reducing false positives. This is a common tuning technique in FortiGate IPS where you can create exceptions for specific sources or destinations to avoid unnecessary alerts from benign traffic.

Answer

Enabling hardware acceleration for IPS processing.

Answer

Increasing the sensitivity of signatures to catch more attacks.

Question 10

An administrator runs 'diagnose debug application ike -1' and sees the following output:
ike 0:come to x.x.x.x:500, IKEv1, cookie 123456789abcdef0
ike 0:incoming IKE packet: src y.y.y.y:500, dst x.x.x.x:500, len 456
ike 0:send IKE packet: src x.x.x.x:500, dst y.y.y.y:500, len 456
ike 0:phase 1 negotiation failed due to time out.
What is the likely cause?

Accepted Answer

A firewall rule is blocking UDP 500/4500 between the peers. The output shows that the IKE packet is being sent and received (no proposal mismatch or interface down), but the negotiation fails due to a timeout. This indicates that the packet is leaving the local FortiGate but the response is not arriving back, which is classic behavior when a firewall (or ACL) between the peers is blocking UDP 500 or 4500. The timeout occurs because the remote peer never receives the initial packet or the local peer never receives the reply, preventing any IKE exchange from completing.

Answer

The remote FortiGate's Phase 1 proposal does not match

Answer

The pre-shared key is incorrect

Answer

The local FortiGate's external interface is down