NSE4 Timed Practice Test 2 — 10 Questions

Question 1

Which TWO are best practices for configuring IPsec VPN on FortiGate to ensure high availability and security?

Accepted Answer

Enable perfect forward secrecy (PFS) for phase2 to ensure session keys are not compromised if a private key is stolen.. Perfect Forward Secrecy (PFS) ensures that if an attacker compromises the private key used during IKE phase1, they cannot derive the session keys used in phase2. By requiring a new Diffie-Hellman exchange for each phase2 rekey, PFS isolates the compromise to only the current session, protecting past and future encrypted traffic. This is a critical security best practice for IPsec VPNs on FortiGate.

Answer

Disable DPD on the phase1 interface to reduce overhead.

Answer

Use aggressive mode for faster IKE negotiation.

Answer

Disable PFS to reduce CPU load on the firewall.

Question 2

A FortiGate is configured in an A-P HA cluster. The administrator wants to ensure that session failover occurs for UDP-based voice traffic. Which TWO settings must be enabled?

Accepted Answer

Enable UDP session synchronization.. Option A is correct because UDP session synchronization must be enabled to replicate UDP session state between HA cluster members, ensuring that active sessions for voice traffic (which typically uses UDP) are seamlessly taken over by the standby unit during a failover. Without this setting, UDP sessions are not synchronized by default, and voice calls would drop.

Answer

Set HA override to enabled.

Answer

Enable configuration synchronization.

Answer

Set failover hold time to 1 second.

Question 3

An administrator needs to configure a FortiGate to allow web traffic from the internal network to the Internet. The internal network is 192.168.1.0/24 and the WAN interface is port1 with IP 203.0.113.1. Which firewall policy is correct?

Accepted Answer

Source: internal, Destination: port1, Service: HTTP/HTTPS, Action: ACCEPT. Option A is correct because the firewall policy must match traffic originating from the internal network (source: internal) destined for the Internet via the WAN interface (destination: port1), and the service must be restricted to HTTP/HTTPS to allow web traffic only. The action ACCEPT permits the traffic. This aligns with the standard stateful inspection flow where source and destination interfaces are defined based on traffic direction.

Answer

Source: port1, Destination: internal, Service: HTTP/HTTPS, Action: ACCEPT

Answer

Source: external, Destination: internal, Service: HTTP/HTTPS, Action: ACCEPT

Answer

Source: internal, Destination: port1, Service: ALL, Action: ACCEPT

Question 4

Refer to the exhibit. The FortiGate has two default routes. The administrator attempts to ping 8.8.8.8 from the CLI and receives no response. What is the most likely reason?

Accepted Answer

The gateway 203.0.113.1 (port1) is unreachable. When a FortiGate has multiple default routes, it uses the route with the lowest distance (administrative distance) as the primary route. If the gateway for the primary route (203.0.113.1 on port1) is unreachable, the FortiGate will not be able to reach 8.8.8.8, even if a secondary default route exists. The ping fails because the device cannot ARP for the gateway or the next-hop is down, causing the route to be inactive.

Answer

The second route is overwriting the first route

Answer

Both routes are equal-cost and load-balancing is not working

Answer

The configuration is invalid because duplicate default routes are not allowed

Question 5

A FortiGate administrator is troubleshooting a problem where users cannot access the Internet. The FortiGate has a default route pointing to the ISP gateway. The administrator runs 'execute ping 8.8.8.8' from the FortiGate CLI and it succeeds. However, internal users behind NAT are unable to reach external servers. Which is the most likely cause?

Accepted Answer

No NAT policy is configured for internal users. The administrator confirmed that the FortiGate itself can reach the Internet (ping 8.8.8.8 succeeds), so the default route and basic connectivity are working. However, internal users behind NAT cannot reach external servers, which indicates that traffic from internal users is either not being translated or is being blocked. The most likely cause is that no NAT policy (or firewall policy with NAT enabled) exists to perform source NAT for internal users, so their private IP addresses are not translated to the FortiGate's public IP, and the ISP gateway drops the packets because private addresses are not routable on the Internet.

Answer

The default route is incorrectly configured

Answer

An implicit deny policy is blocking traffic from internal to external

Answer

External access profile is set to read-only

Question 6

A network administrator configures a firewall policy to allow HTTP traffic from the internal network (10.0.0.0/8) to a web server (172.16.1.10). Users on the 10.0.0.0/8 network cannot access the web server, but other internal users can. The administrator checks the policy list and sees the policy is enabled and in the correct position. What is the most likely cause?

Accepted Answer

The firewall does not have a route to the 10.0.0.0/8 network. The most likely cause is that the firewall does not have a route to the 10.0.0.0/8 network. Even though the policy is enabled and correctly positioned, the firewall must have a return route to the source network (10.0.0.0/8) for the web server's response traffic to reach the users. Without this route, the firewall drops the return packets, causing connectivity failure for those specific users.

Answer

The policy is placed below a deny-all policy

Answer

NAT is not configured on the policy

Answer

The policy is disabled

Question 7

Refer to the exhibit. An administrator runs 'diagnose firewall auth list' and sees two authenticated users. The firewall policy requires authentication for HTTP traffic from 10.0.0.0/24 to 192.168.1.10. User 'jsmith' has been idle for 20 minutes, but the authentication session is still active. The idle timeout is set to 30 minutes. What will happen after 30 minutes of inactivity?

Accepted Answer

The authentication session will expire, and the user must re-authenticate for new traffic. Option D is correct because the authentication idle timeout of 30 minutes governs the authentication session, not the firewall session. Once the user 'jsmith' has been idle for 30 minutes, the authentication session expires. Any new HTTP traffic from 10.0.0.0/24 to 192.168.1.10 will then require re-authentication, as the firewall policy enforces authentication for that traffic. The existing firewall session may persist briefly, but it will not allow new traffic without a valid authentication entry.

Answer

The authentication session will remain active because the firewall session is still valid

Answer

The user will be automatically re-authenticated without prompting

Answer

The firewall session will be torn down immediately

Question 8

A company with multiple remote sites uses IPsec VPNs. One site reports intermittent connectivity. The administrator checks the logs and sees 'IPsec phase 2 negotiation failed' messages. Which configuration change is most likely to resolve the issue?

Accepted Answer

Enable Dead Peer Detection (DPD) on the Phase 1 interface.. Intermittent IPsec phase 2 negotiation failures often occur when one peer's Phase 2 security association (SA) expires while the other peer still considers it valid, causing a mismatch. Enabling Dead Peer Detection (DPD) on the Phase 1 interface allows the FortiGate to actively probe the peer's liveness and renegotiate Phase 1 and Phase 2 SAs before they expire, preventing the state mismatch that leads to intermittent failures.

Answer

Change the encryption algorithm from AES256 to 3DES.

Answer

Increase the Phase 2 lifetime.

Answer

Enable NAT traversal.

Question 9

A FortiGate administrator is troubleshooting a high CPU usage issue. The 'get system performance status' command shows that the CPU usage is consistently above 80% with no traffic. Which of the following is the most likely cause?

Accepted Answer

A process such as the IPS engine is stuck in an infinite loop.. When CPU usage remains high (above 80%) with no traffic, the most likely cause is a process stuck in an infinite loop, such as the IPS engine. This is a known software bug or process hang that consumes CPU cycles even without network traffic, and it can be verified using 'diagnose sys top' to identify the offending process.

Answer

An interface is in error-disable state causing CPU interrupts.

Answer

The firewall policy is misconfigured, causing packet drops.

Answer

A DDoS attack is overwhelming the CPU.

Question 10

An administrator needs to configure a FortiGate to send logs to two different syslog servers for redundancy. Which configuration method should be used?

Accepted Answer

Under 'config log syslogd setting', set 'status enable' and then add multiple servers using 'set server '.. Option A is correct because FortiGate's syslog configuration allows you to specify multiple syslog servers in a single 'config log syslogd setting' block by using the 'set server' command with a space-separated list of IP addresses. This enables redundant log delivery without requiring separate configuration blocks or external devices. The FortiGate will attempt to send logs to the first server; if it fails, it automatically fails over to the next server in the list.

Answer

Configure two separate log settings for each server.

Answer

Configure one syslog server and use a load balancer.

Answer

Use a FortiAnalyzer to forward logs to syslog servers.