Pass the Fortinet NSE 7 Network Security Architect NSE7_FSN_AR-7.6 Questions and answers with CertsForce

When FortiGate performs SSL certificate inspection with default settings, it checks if the Server Name Indication (SNI) matches either the Common Name (CN) or any Subject Alternative Name (SAN) in the server certificate. If there is no match, FortiGate does not block the connection; instead, it uses the CN value from the certificate ' s subject field to continue web filtering and categorization.

This behavior is described in the official Fortinet 7.6.4 Administration Guide:

“Check the SNI in the hello message with the CN or SAN field in the returned server certificate: Enable: If it is mismatched, use the CN in the server certificate.” This is the default (Enable) mode, which differs from the Strict mode that would block the mismatched connection.

By default, this policy ensures service continuity and prevents disruptions due to certificate mismatches, allowing FortiGate to log and inspect based on the CN even when the requested SNI does not match. It provides a balance between connection reliability and the accuracy of filtering by certificate identity, allowing security policies to remain functional without unnecessary blocks. This approach is recommended by Fortinet to maintain usability for end-users while still supporting granular inspection.

Analyze the " Send to Application Layer " Message:

The most critical line in the debug output is: id=65308 ... func=av_receive ... msg= " send to application layer "

Meaning: This message indicates that the FortiGate kernel is handing the packet over to a user-space daemon (specifically the WAD/Proxy process, indicated by av_receive handlers) for deep inspection.

Implication: This behavior is the hallmark of Proxy-based inspection. In Flow-based inspection, the traffic is handled by the IPS engine (often within the kernel or via specific IPS handlers like ips_measure), and you would not typically see a " send to application layer " message for standard web filtering.

Evaluate Option B (Firewall Policy Mode):

Since the traffic is being sent to the application layer proxy, the Firewall Policy controlling this traffic (Policy ID 1, as seen in Allowed by Policy-1) must be configured with Inspection Mode = Proxy. If it were Flow-based, the traffic would stay in the flow path. Thus, Option B is correct.

Evaluate Option C (Web Filter Profile Mode):

In FortiOS, when a firewall policy is set to Proxy-based inspection, the security profiles (like Web Filter) applied to that policy also operate in Proxy-based inspection mode. The presence of the av_receive function confirms that the content inspection (Web Filter/AV) is being performed by the proxy engine. Thus, Option C is correct.

Why Option A is Incorrect (NPU Offload):

The output shows npu_state=0x100. In the context of a flow trace where traffic is being " sent to application layer, " this confirms the session is not fully offloaded to the NPU (Network Processor). Offloaded traffic (Fast Path) is handled by the hardware and would not generate these specific CPU-level debug logs for the payload inspection phase. The proxying process requires CPU intervention.

Why Option D is Incorrect (Port Mapping):

While valid protocol mapping is necessary for inspection, the specific debug output shown is a direct result of the Inspection Mode (Proxy vs. Flow). The observation of the traffic moving to the application layer is primarily caused by the policy and profile mode settings, making B and C the direct " observations " derived from the log data.

The session output reveals a session with proto=1 (ICMP) and the origin and reply directions show address and NAT translations. Specifically, the hook=post dir=org act=snat shows that source NAT is performed for outgoing packets, where the source 10.1.10.10:40602 is translated to 10.200.5.1:8 (likely ICMP id 8, not a TCP/UDP port). The reply direction, hook=pre dir=reply act=dnat, indicates destination NAT for incoming packets: packets incoming for 10.200.5.1:60430 are destination-NATed to 10.1.10.10:40602. The gateway (gwy) is listed as 10.200.1.254/10.1.0.1, which for outgoing traffic means that return traffic is directed to the gateway (10.200.1.254), per the NAT policy. This is confirmed by the FortiOS Session Table Guide, which explains that the returned ICMP reply will be routed out to this NAT gateway. The session statistics and logical flow (SNAT out, matching DNAT in) reinforce that reply traffic to the initiator traverses via 10.200.1.254.

The IKE_SA_INIT exchange in IKEv2 is responsible for DoS protection measures. During IKE_SA_INIT, before authentication and further exchange, the responder can use cookie challenges (per RFC 7296 and Fortinet VPN documentation). If a DoS attack is suspected (many requests from the same source), the responder replies with a cookie. Only after the initiator returns the correct cookie does the exchange proceed, protecting the responder from state exhaustion and certain forms of DoS traffic at the handshake stage.

To identify the reason for the lack of prefixes, we must interpret the State/PfxRcd and Up/Down columns in the get router info bgp summary exhibit.

Analyze Neighbor Status:

Neighbor 10.125.0.60: State is OpenSent. This session is not established. It is stuck in the negotiation phase.

Neighbor 100.64.3.1: State is Active. This session is not established. The router is actively trying to initiate a TCP connection.

Neighbor 10.127.0.75:

Up/Down: 02:45:55. This indicates the BGP session has been Up (Established) for almost 3 hours.

State/PfxRcd: 0. This number represents the count of prefixes received. The session is fully established, but the neighbor has sent zero routes.

Determine the Cause:

Since the session with 10.127.0.75 is established, connectivity and handshakes (Options A, B, C) are not the issue for this neighbor.

The fact that it is Up but sending 0 prefixes strongly implies that the neighbor is configured to filter out its routes before sending them to the local FortiGate.

Option D correctly identifies this as a RIB-OUT (Routing Information Base - Outbound) configuration issue on the neighbor (Router 10.127.0.75), which prevents it from advertising its routes.

The correct answer is D. The inbound IPsec SA was copied to the NPU.

The exhibit shows:

npu_flag=02

dec_npuid=1

enc_npuid=0

The study guide gives the exact meaning of the npu_flag field:

npu_flag=00 = Both IPsec SAs loaded to the kernel

npu_flag=01 = Outbound IPsec SA copied to NPU

npu_flag=02 = Inbound IPsec SA copied to NPU

npu_flag=03 = Both outbound and inbound IPsec SAs copied to NPU

It also explains: “If the first IPsec packet is inbound and can be offloaded, the inbound SA is copied to the NPU and the npu_flag changes to 02. After both SAs are copied to the NPU, the npu_flag changes to 03.”

So with npu_flag=02, only the inbound SA has been copied to the NPU. That makes D correct.

Why the other options are wrong:

A is wrong because outbound-only offload would be npu_flag=01, not 02

C is wrong because both directions offloaded would be npu_flag=03, not 02

B is wrong because dec_npuid=1 identifies the NPU ID used for decryption, but it does not state that the processor is specifically NP6. The study guide only maps the offload state through the npu_flag values in this context, not the NPU model from this field alone

So the verified answer is: D.

The administrator is running a packet sniffer with the filter ' udp port 500 or udp port 4500 or esp ' . The result is " no output, " even though the VPN is attempting to establish (failing).

A. The VPN is configured to use IKE over TCP:

Standard IPsec IKE negotiation uses UDP port 500 (IKE) and UDP port 4500 (NAT-T).

However, if IKEv2 over TCP (RFC 8229) or Fortinet ' s proprietary IKE over TCP is configured (often used to bypass firewalls that block UDP), the traffic will use TCP (often port 4500 or 443).

The sniffer filter explicitly looks for udp or esp (IP Protocol 50).

If the traffic is encapsulated in TCP, it matches tcp protocol, not udp or esp (raw ESP). Therefore, the sniffer sees zero packets matching the filter.

Why other options are incorrect:

B: esp is a valid argument for diagnose sniffer packet. It is equivalent to filtering for IP protocol 50.

C: If the ISP were blocking traffic, the sniffer (running on the local FortiGate) would still see the outbound packets generated by the FortiGate trying to initiate the connection. " No output " implies the local device isn ' t even generating packets matching that filter.

D: Mismatched IKE versions would still generate IKE negotiation packets (proposals/errors) that would be captured by the sniffer.

We must analyze the flags (*, > , S, O, B) and Administrative Distances (AD) shown in the get router info routing-table database exhibit to determine the correct statements.

Analysis for Option A (The BGP route to 10.0.4.0/24 is not in the forwarding information base):

True. Look at the entry for 10.0.4.0/24.

There is an OSPF route: O * > 10.0.4.0/24 [110/2]. The * indicates it is in the FIB, and > indicates it is the selected route.

There is a BGP route: B 10.0.4.0/24 [200/10]. This line lacks the * flag.

Reason: The OSPF route has an Administrative Distance of 110. The BGP route (iBGP) has an AD of 200. Since 110 is lower than 200, OSPF wins, and the BGP route is not installed in the Forwarding Information Base (FIB).

Analysis for Option B (The default static route through 10.200.1.254 is in the forwarding information base):

True. Look at the 0.0.0.0/0 entries.

The first entry is S * > 0.0.0.0/0 [10/0] via 10.200.1.254.

The * flag confirms this specific route is installed in the FIB.

The second static route (via 10.200.2.254) has a higher distance ([20/0]) and no * flag, so it is inactive.

Why C is False: ECMP (Equal Cost Multi-Path) requires routes to have the same cost/priority. Here, one static route has AD 10 and the other has AD 20. They are not equal, so ECMP is not performed.

Why D is False: The routing table database shows active routes, not the raw Link State Advertisement (LSA) database. You cannot determine the number of LSAs received solely from this output.