FCSS_NST_SE-7.6 Exam Dumps - Fortinet Certified Solution Specialist Questions and Answers

FortiTelemetry is a critical part of Security Fabric communications and requires explicit configuration for each participating FortiGate interface. The administrative access setting " fabric " (corresponding to FortiTelemetry) must be manually enabled per interface on both upstream and downstream devices. This is performed in the GUI under Administrative Access or via the CLI using the command set allowaccess fabric for the relevant network interface. Without this step, FortiTelemetry communications will not occur on that interface.

Additionally, the default communication between downstream and upstream FortiGate units in the Security Fabric is over TCP port 8013. This port is well-documented as the standard for Security Fabric and FortiTelemetry connections, and must be open and permitted across the network path for connectivity and status enforcement between units. The downstream FortiGate initiates the connection to the upstream via this port unless otherwise configured. This has also been documented as a PCI-relevant port, showing its default usage.

Other options:

Neighbor Discovery in FortiOS uses IPv6 ND protocol, not TCP.

FortiTelemetry port (8013) can be modified, but the interface Administrative Access for the Security Fabric must be manually enabled; Neighbor Discovery port modification is not documented as a supported change for FortiGate.

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.

The correct answers are A, D, and E . This is a feasible path RPF check scenario. In FortiGate’s default RPF behavior, FortiGate checks whether the routing table contains a valid return route to the source IP address through the same interface on which the packet arrived . The study guide’s RPF feasible path example states that FortiGate “checks the routing table for a route that matches the source address and incoming interface of the first original packet.” It then gives the exact result: User A passes because “there is a default route through wan1,” so packets received on wan1 pass the RPF check regardless of source address. User B fails because FortiGate does not have a route to 95.56.234.24 through wan2 . User C fails because FortiGate does not have a route to 10.0.4.63 through port1 . Therefore, option B is wrong because FortiGate is not allowing asymmetric return routing here. Option C is wrong because the default route points out wan1 , not port1 , so it cannot validate User C’s packet arriving on port1.

The correct answer is C. 64.26.151.37 .

The study guide explains the FortiGuard flags shown by diagnose debug rating:

D = Default

I = Initial

T = Timing

F = Failed and specifically: “F = The server is down”

So even though 121.111.236.179 has the lowest RTT in the exhibit, it has the F flag, meaning FortiGate considers that server failed/down , so it will not be chosen.

To determine which active server is selected, the FortiOS administration guide states:

“The server list is sorted first by weight. The server with the smallest RTT appears at the top of the list regardless of weight. … Therefore the top position in the list is selected based on RTT while the other positions are based on weight.”

Among the valid, non-failed choices in the exhibit:

64.26.151.37 → RTT 45

209.22.147.36 → RTT 103

96.45.33.65 → RTT 144

208.91.112.194 → RTT 107

The active server with the lowest RTT is 64.26.151.37 , so that is the server FortiGate will choose.

So the verified answer is: C .

The study guide states:

“The kernel memory slabs are collections of objects with a common purpose. The kernel uses them to store information in memory.”

It also gives the exact calculation rule:

“Total slab size = available objects x object size”

From the exhibit:

tcp_session 3 5 1500 ...

So:

available objects = 5

object size = 1500

Therefore:

Total slab size = 5 × 1500 = 7500 kB

That makes D correct, and it is associated with the kernel , not user space.

Why the other options are wrong:

A is wrong because sctp_session 0 0 1600 ... gives 0 × 1600 = 0 , but slabs are associated with the kernel , not user space.

B is wrong because ip_session 1 3 1200 ... gives 3 × 1200 = 3600 , but again slabs are kernel memory, not user space.

C is wrong because ip6_session 0 0 1300 ... gives 0 × 1300 = 0 , not 1300.

The output on FGT-01 confirms that the device is actively encapsulating traffic and sending it as ESP packets (Protocol 50) out of port1 towards the IP address 97.86.16.52. The logs show outgoing packets, which confirms FGT-01 is attempting to initiate or maintain the tunnel and that NAT-Traversal is not being used (as it uses raw ESP).

The output on FGT-02 , however, displays (no packets captured). This is significant because the sniffer command diagnose sniffer packet any ' esp ' captures traffic at the network interface level (ingress), regardless of whether a matching VPN configuration exists on the receiving unit. The absence of packets proves that the ESP traffic generated by FGT-01 is physically not arriving at FGT-02 ' s interface.

This behavior is explained by two primary factors:

Option A (Blocking): An intermediate device, such as an ISP router or firewall, is dropping Protocol 50 traffic. Unlike UDP 500/4500, raw ESP is often blocked by default on many networks or legacy devices.

Option C (Routing/Misconfiguration): If the administrator configured the wrong remote peer IP on FGT-01 , the packets are being routed to a different destination entirely. Consequently, they never arrive at FGT-02 to be captured.

Option B is incorrect because even without a configured VPN tunnel, the sniffer would still display the incoming ESP packets if they were reaching the interface. Option D is incorrect because FGT-01 is sending ESP, making ' esp ' the correct filter.