Free Fortinet NSE4_FGT_AD-7.6 Practice Exam with Questions & Answers | Set: 2

“IKE uses UDP port 500. If NAT-T is enabled in a NAT scenario, IKE uses UDP port 4500.”

“IKEv2 provides a simpler operation, which is the result of using a single exchange mode and requiring less messages to bring up the tunnel.”

For the specific workaround asked in this question, Fortinet’s official documentation states that for an IP-level VPN, SSL VPN tunnel mode is useful to avoid issues caused by intermediate devices such as “ESP packets being blocked,” “UDP ports 500 or 4500 being blocked,” and “fragments being dropped, causing IKE negotiation that uses large certificates to fail if the peer does not support IKE fragmentation.” ( Fortinet Document Library )

Fortinet’s official documentation also states: “The ip-fragmentation command controls packet fragmentation before IPsec encapsulation, which can benefit packet loss in some environments.” ( Fortinet Document Library )

Technical Deep Dive:

The correct answers are A and B .

A is correct because SSL VPN tunnel mode can bypass the classic IPsec transport problems caused by intermediate devices filtering ESP or blocking UDP 500/4500 . Fortinet explicitly documents this as a practical workaround. ( Fortinet Document Library )

B is correct because enabling fragmentation helps when IKE negotiation uses large certificates and fragments are being dropped in transit. Fortinet documents this exact failure scenario and the related fragmentation control. ( Fortinet Document Library )

Why the others are not correct:

C is not the key fix. Hub-and-spoke is a topology choice, not the actual mechanism that solves blocked ESP or UDP 500/4500.

D is not sufficient for this problem. IKEv2 uses fewer messages, but it still relies on IPsec/IKE transport and does not itself solve intermediate devices blocking ESP or UDP 500/4500. The source PDF mentions simpler operation, not blocked-port avoidance.

So, the two effective fixes are:

Use SSL VPN tunnel mode

Enable fragmentation

NetAPI: Polls temporary sessions created on the DC when a user logs on or logs off and calls the NetSessionEnum function on Windows. It’s faster than the WinSec and WMI methods; however, it can miss some logon events if a DC is under heavy system load. This is because sessions can be quickly created and purged form RAM, before the agent has a chance to poll and notify FG.

Exact Extract:

“If you want the wizard to configure the VPN for you, then select the template type Site to Site, Hub-and-Spoke, or Remote Access that best matches your VPN.”

“Use remote access VPNs when remote internet users need to securely connect to the office to access corporate resources. The remote user connects to a VPN server located on the corporate premises, such as FortiGate, to establish a secure tunnel.”

“A common use of the IPsec wizard is for configuring a remote access VPN for FortiClient users.”

Technical Deep Dive:

The correct answer is A. Remote Access .

A sales employee travelling abroad is a remote user , not another branch office or headquarters firewall. That means the tunnel type is a remote access VPN , where the user connects from an internet location back to the corporate FortiGate. In this design, the remote client typically uses FortiClient , and FortiGate acts as the VPN server.

Why the other options are incorrect:

Hub-and-Spoke is for multi-site branch connectivity through a central hub.

Site-to-Site is for connecting two fixed networks, such as branch office to headquarters.

Dial-up User describes the remote-user behavior conceptually, but it is not the IPsec Wizard template choice shown in the study guide. The wizard template to select is Remote Access .

So for a travelling sales employee, the administrator must choose the Remote Access VPN Wizard template.

Based on the FortiOS 7.6 Administrator Guide regarding Fortinet Single Sign-On (FSSO) polling modes, the agentless polling mode has specific technical characteristics:

SMB Protocol Usage (Statement B is True):

In agentless polling mode, the FortiGate unit itself acts as the collector.

It establishes direct connections to the Windows Domain Controllers (DCs) using the SMB (Server Message Block) protocol, typically over TCP port 445, to read the Windows Security Event logs.

This allows FortiGate to parse login event IDs (such as 4768 and 4769) to identify users and their corresponding IP addresses without needing an external collector agent installed on a server.

Workstation Check Support (Statement C is True):

One of the primary limitations of the agentless polling mode compared to the agent-based mode is the lack of workstation verification.

In agentless mode, FortiGate does not perform " workstation checks " or " dead entry checks " . This means it cannot proactively verify if a user is still logged into a specific workstation after the initial logon event is recorded, which can lead to stale entries if a user logs off without a corresponding event being captured.

Why other options are incorrect:

Option A: In agentless mode, FortiGate (the FSSO daemon) performs the collection itself; it does not use the AD server as a " collector agent " in the functional sense of FSSO architecture.

Option D: While FortiGate uses LDAP to retrieve group membership information once a user is identified, it does not " direct " a collector agent to a remote LDAP server, as there is no external collector agent involved in this specific mode.

A closely related routing principle from the guide is:

“For each session, FortiGate performs two route lookups... After completing these two lookups, FortiGate writes the routing information to its session table. Subsequent packets are routed according to the session table, not the routing table.”

Also, the guide notes an HA limitation that helps explain the same design principle for FortiGate-terminated sessions:

“Enabling session pickup allows active sessions to be seamlessly handed picked up by the new primary in the event of an HA failover... Note that there are some limitations to this – for example, any sessions that terminate at the FortiGate itself ( e.g. SSL VPN, proxy sessions ) cannot be handed off to another FortiGate and must be restarted on the new primary.”

Technical Deep Dive:

The correct answer is D .

In multi-WAN environments, session preservation is used so that traffic for sessions that are tightly bound to the FortiGate interface they terminate on—most notably SSL VPN and other FortiGate-terminated flows—does not suddenly switch to another egress interface just because the routing table changes. Those sessions are sensitive to interface consistency. If replies start leaving through a different WAN after a route recalculation, the remote peer may see an address/interface mismatch and the session can break.

That means:

A is the opposite of session preservation. Preservation is meant to avoid moving active sessions around.

B is not the purpose of the feature.

C is unrelated.

D correctly describes why an administrator would enable it.

Operationally, this matters most for SSL VPN , management-plane flows, and other sessions that terminate on the FortiGate itself , not just ordinary transit traffic. Transit sessions are generally tracked in the session table and can often survive normal routing behavior more gracefully, but FortiGate-terminated sessions are much more sensitive to WAN/interface changes.

In FortiSASE site-based (remote internet access) deployments, FortiExtender is used to onboard branch or remote sites without a local FortiGate.

According to FortiSASE and FortiExtender architecture documentation:

FortiExtender integrates with FortiSASE using a secure VXLAN-over-IPsec tunnel

This tunnel:

Extends the site network to FortiSASE

Transparently forwards traffic for inspection

Preserves network segmentation and routing context

This design is similar to cloud-based LAN extension and is not proxy-based

Why the other options are incorrect

B: FortiClient is used for agent-based user access, not FortiExtender

C: Secure Web Gateway (SWG) is a service, not a transport mechanism

D: PAC files and explicit proxies are used in agentless / proxy-based access, not site-based FortiExtender deployments

The issue occurs because Facebook still belongs to the Social Networking category, and that category is configured with a Block action. A static URL filter entry with Monitor or Allow does not fully bypass later FortiGuard category filtering. In FortiOS web filtering, static URL filtering is evaluated before FortiGuard category filtering. The Exempt action is specifically used for trusted URLs that must bypass the remaining security inspections and category-based web filtering decisions. Therefore, to allow only Facebook while keeping the Social Networking category blocked, the administrator must configure the static URL filter entry for www.facebook.com with the action Exempt. Changing the entire Social Networking category to Warning would weaken the intended policy, and changing the URL type or feature set does not directly override the category block.

From the exhibits, there are three relevant firewall policies from LAN (port4) to WAN (port2), each using a different IP pool for source NAT:

TCP traffic

Service: ALL_TCP

Destination: BR1-FGT

IP Pool: SNAT-Pool → 100.65.0.49

PING traffic

Service: PING

Destination: all

IP Pool: SNAT-Remote1 → 100.65.0.99

IGMP traffic

Service: IGMP

Destination: all

IP Pool: SNAT-Remote → 100.65.0.149

The user on HQ-PC-1 (10.0.11.50) is pinging BR1-FGT (100.65.1.111). In FortiOS, policy matching is based on (among other fields) source, destination, and service, and the first matching policy in top-down order is applied.

Because the traffic is ICMP echo (ping), it matches the policy named PING traffic (service PING, destination all). That policy explicitly uses Use Dynamic IP Pool with SNAT-Remote1, which is configured with external IP 100.65.0.99.

Therefore, the source NAT IP used for this ping is 100.65.0.99.