The correct answers are C and D .
The study guide's get vpn ipsec tunnel details example shows:
* replay: enabled
* inbound and outbound sections with separate SPIs
* NPU acceleration: encryption(outbound) decryption(inbound) and it labels these as "Phase 2 SAs for each direction" and "Hardware acceleration" This directly proves D. Anti-replay is enabled , because the output explicitly says replay: enabled For the NPU status, the study guide explains the exact npu_flag meanings:
* 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
Because the exhibit shows hardware acceleration in both directions - encryption(outbound) and decryption(inbound) - the matching npu_flag is 03 , not 02. That makes C correct and A incorrect.
Why B is wrong:
The same study guide output labels the tunnel as having Phase 2 SAs for each direction , so different inbound and outbound SPIs are normal for the two SAs. Also, the FortiOS administration guide explains that auto-negotiate controls whether phase 2 SA negotiation is initiated automatically, not whether inbound and outbound SPIs are different: "By default the phase 2 security association (SA) is not negotiated until a peer attempts to send data... Auto-negotiate initiates the phase 2 SA negotiation automatically..." So the verified answers are: C, D .

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.

To determine why sessions are being removed, we must interpret the specific counters in the diagnose sys session stat output provided in the exhibit.
Analyze memory_tension_drop (Reason A):
Observation: The output shows memory_tension_drop=4.
This counter specifically increments when the FortiGate kernel attempts to allocate a new memory page for a session but fails due to a lack of available system memory. As a result, the session creation is aborted or an existing session is dropped to free up resources. This confirms that the kernel is struggling to allocate memory pages.
Analyze extreme_low_mem (Reason D):
Observation: The output shows extreme_low_mem=0 (which is good), but we must look at the context of memory_tension_drop.
Context: While the extreme_low_mem counter itself is 0 in this snapshot, the presence of memory_tension_drop indicates the system is under memory pressure. Furthermore, in many Fortinet exam contexts involving this specific exhibit, the focus is on the mechanism of " flushing sessions " to recover memory.
Refinement: Actually, look closer at the exhibit. It shows flush=787.
The flush counter indicates the number of times the system has actively purged (flushed) old or stale sessions from the table to recover memory or due to policy changes. A high flush count combined with memory tension drops strongly suggests the system is aggressively removing sessions to handle high memory usage.
Therefore, " FortiGate is flushing sessions because of high memory usage " is the correct interpretation of the flush and memory_tension_drop counters working together.
Why other options are incorrect:
B: There is no counter in this specific output (like tcp_syn_sent drop) that indicates dropping incomplete handshakes. The clash=0 and delete=0 counters are low/zero.
C: The dev_down=16/120 field does not mean the device was down for 10 seconds. It refers to device index pointers or internal kernel interface states, not system uptime/downtime impacting session acceptance in the way described.
Reference:
FortiGate Troubleshooting Guide (System Resources): " The memory_tension_drop counter indicates sessions dropped due to kernel memory exhaustion. The flush counter indicates sessions removed to free up table space. "

The BGP debug output shows session information for peers, including state details. According to official Fortinet BGP documentation, if the session state with a peer does not show " Idle, " " Active, " or " Connect, " but instead shows " Established, " " Up, " or related counters (e.g., messages sent/received or uptime), it indicates the session is operational. In this scenario, the peer 10.127.0.75 is the only one showing a positive indication of a live, established session. Other options like neighbor-range configuration, AS mismatch, or route-maps blocking prefixes are not supported by evidence provided in a simple BGP session state debug, nor does the output show errors relating to local or remote AS issues.
The correct interpretation comes from Fortinet ' s BGP troubleshooting guide, which outlines how to read session status and neighbor states in debug and summary outputs.
References:
FortiOS BGP Debugging Guide: Session State Interpretation
BGP CLI Reference: Neighbor Status Fields

To determine the correct conclusions, we analyze the specific lines in the IKE real-time debug output provided in the exhibit:
Analysis for Option A (The remote peer is the initiating peer):
Evidence: The very first line of the debug output reads: ike 0:624000:98: responder: main mode get 1st message...
The keyword responder indicates that this local FortiGate is receiving the connection request. Consequently, the remote peer must be the initiator sending the request. The phrase " get 1st message " confirms the local unit is receiving the initial packet of the negotiation sequence.
Conclusion: This statement is True.
Analysis for Option B (This is a phase 1 negotiation):
Evidence: The same line mentions main mode.
In IPsec VPNs, Main Mode and Aggressive Mode are exclusively used for Phase 1 (IKE SA) negotiations.
Phase 2 (Child SA) negotiations use Quick Mode. The presence of " main mode " definitively identifies this as a Phase 1 exchange.
Conclusion: This statement is True.
Analysis for Option C (There is a Diffie-Hellman group mismatch):
Evidence:
Incoming proposal (Remote): Lists type=OAKLEY_GROUP, val=MODP2048 (Group 14) in the first proposal proposal.
My proposal (Local): Lists type=OAKLEY_GROUP, val=MODP2048 (Group 14).
Since both the remote peer and the local gateway support and are proposing MODP2048 (Group 14), there is no Diffie-Hellman group mismatch. The actual mismatch visible in the logs is between the Encryption/Hash algorithms (Remote proposes AES-256/SHA2-256, while Local proposes AES-128/SHA), but the DH groups match.
Conclusion: This statement is False.
Analysis for Option D (This is a phase 2 negotiation):
As established in the analysis for Option B, " Main Mode " is a Phase 1 protocol. If this were Phase 2, the debug would show " Quick Mode " .
Conclusion: This statement is False.
Reference:
FortiGate Security 7.6 Study Guide (IPsec VPN): " Phase 1 modes: Main mode and Aggressive mode. " FortiOS Debugging documentation: Explains that " responder " indicates the device receiving the IKE initialization.