FCSS_NST_SE-7.6 Exam Dumps - Fortinet NSE 6 - Network Security 7.6 Support Engineer

The correct answers are A and C .

The exhibit shows that preserve-session-route is enabled on port1:

config system interface

edit " port1 "

set preserve-session-route enable

next

end

The study guide explains the effect of this setting exactly:

“enable: FortiGate marks existing session routing information as persistent, and applies only the modified routes to new sessions”

It also states:

“The current route must still be present in the FIB. Otherwise, FortiGate flags the session as dirty and reevaluates it”

And the same page further clarifies:

“If you enable this setting, sessions passing through that interface continue to pass without being affected by the routing changes. The routing changes apply only to new sessions. If the route is removed from the FIB, then FortiGate must flag the session as dirty, flush its gateway information, and reevaluate the session.”

This proves:

A is correct because with preserve-session-route enable, existing sessions are normally preserved and routing changes apply only to new sessions.

C is correct because the session remains unchanged unless the current route is removed from the FIB/routing table, in which case FortiGate dirties and reevaluates the session.

Why the other options are wrong:

B is wrong because when the active route is removed, FortiGate does not simply mark the session dirty and stop there. The study guide says it “flags the session as dirty and reevaluates it” , which means route lookup happens again.

D is wrong because the session does change if the active route is removed. FortiGate flushes gateway information and reevaluates the session.

So the verified answers are: A, C .

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 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 .

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.

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.

The correct answer is C. The session is offloaded using NPU .

The exact session example in the study guide shows:

proto=6 → this is a TCP session

expire=3599 → the session will expire in 3599 seconds , not in one second

hook=post dir=org act=snat 10.9.31.117:45388- > 200.8.57.5:443(10.1.0.3:45388)

hook=pre dir=reply act=dnat 200.8.57.5:443- > 10.1.0.3:45388(10.9.31.117:45388)

npu info: ... offload=8/8 ...

and the slide explicitly states: “Offloaded in both directions using NP6”

The study guide also explains this exact point clearly:

“Counters for hardware acceleration—The presence of the npu info field indicates the session has been offloaded to hardware acceleration. In this example, traffic is being offloaded in both directions using network processor (NP) 6, which is represented by the value of 8.”

Why the other options are wrong:

A is wrong because expire=3599, not 1. The duration=1 field means the session has existed for 1 second, not that it will expire in 1 second.

B is wrong because the original session is from 10.9.31.117 to the remote server 200.8.57.5:443. The IP 10.1.0.3 is the SNAT-translated source address , not the final destination.

D is not the best answer for this single-select question . The reply is indeed DNATed back toward the original client, but the exact validated takeaway highlighted by the study guide for this exhibit is the NPU offload state .

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.