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

The get router info bgp summary output lists BGP neighbor status:

Prefix Reception: The " State/PfxRcd " column shows the number of prefixes received from the neighbor—neighbor 100.64.1.254 has " 1 " , confirming option A.

Received Message Count: Under " MsgRcvd " , 18 packets have been received from neighbor 100.64.1.254. This matches option C.

The second neighbor 100.64.2.254 is in " Active " state and has received/sent 0 packets, indicating that its TCP connection is NOT established, disproving option B.

There is no indication anywhere that the router is " still calculating " prefixes; " Active " just means no session is established, so option D is incorrect.

The issue is caused by the strict matching logic of the configured Prefix List.

Current State: The rule is edit 1 with set prefix 172.16.0.0 255.255.0.0 and both ge (greater than or equal) and le (less than or equal) are unset.

Behavior: When ge and le are unset, FortiOS requires an exact match of the subnet mask. The current rule only matches the exact network 172.16.0.0/16. It denies 172.16.52.0/24 because the mask (/24) does not match the rule ' s mask (/16).

To fix this and inject 172.16.52.0/24, you must modify the list to match the /24 mask:

A. Add another entry to the prefix list to specifically allow the 172.16.52.0/24 network:

Creating a new rule (e.g., edit 2) with set prefix 172.16.52.0 255.255.255.0 will provide an exact match for the incoming route, allowing it to pass the distribute-list.

B. Change the ge value to 17:

By configuring set ge 17 on the existing rule (conceptually 172.16.0.0/16 ge 17), you change the logic from " exact match " to " range match " .

This configuration tells the router to match any prefix starting with 172.16.x.x that has a subnet mask length of 17 or greater.

Since the incoming route is a /24, and 24 is greater than 17, the route will match the prefix list and be accepted.

Why other options are incorrect:

C: The option text appears to read " Change the ... value to 16 " . If this refers to le 16, it would enforce the mask to be exactly /16 or less, which still excludes /24.

D: Changing the default behavior to implicit allow defeats the purpose of a filter (security control) and is not a standard configuration step for fixing a single missing route.

https://community.fortinet.com/t5/FortiGate/Technical-Tip-Using-the-diagnose-sys-top-CLI-command/ta-p/190238

The correct answer is B .

The study guide states that for TCP , the protocol state is a two-digit number . The first digit is the server-side state and is 0 when the session is not subject to inspection . The second digit is the client-side state . It also shows that value 1 = ESTABLISHED

So, for a normal TCP session with no inspection, proto_state=01 means:

first digit 0 = no inspection

second digit 1 = ESTABLISHED

That makes B correct.

Why the other options are wrong:

A is wrong because for UDP , the study guide says 00 = one-way traffic and 01 = two-way traffic

C is wrong because 10 does not represent the normal established TCP session described in the study guide. The established example shown is based on state value 1 , and the guide explicitly highlights proto_state=11 when both server-side and client-side TCP handshakes are completed

D is wrong because for ICMP , the study guide says “the protocol state is always 00”

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To capture encrypted IPsec phase 2 (ESP) traffic between two FortiGate devices, the correct protocol filter to use is ip proto 50. According to the Fortinet official sniffing and debugging documentation, ESP (Encapsulating Security Payload) is used for encrypted phase 2 payload transfer and always uses IP protocol number 50. Running the command diagnose sniffer packet any ' ip proto 50 '  captures only ESP packets, which represent the encrypted traffic—whether originating or transiting the device.

If there is no NAT device between FortiGates, ESP is not encapsulated in UDP (thus not on UDP port 4500; if NAT-T were required, packets would be UDP-encapsulated, but the scenario explicitly says NAT is not in use). UDP port 500 is for IKE control (negotiation) traffic, and AH (Authentication Header, ip proto 51) is not used for encryption in standard IPsec phase 2 with ESP.

This matches the official CLI reference from Fortinet for VPN and traffic analysis.

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