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 .

To determine the correct reasons for the adjacency failure, we must analyze the standard OSPF real-time debug output (diagnose ip router ospf all enable or diagnose sniffer packet) typically provided in this exam exhibit.
Analyze the Debug Output:
The debug output in this specific question scenario typically displays an incoming Hello packet line: OSPF:
RECV[Hello]: ... auth-type 0 ...
" RECV " : Indicates the packet is coming from the Remote peer.
" auth-type 0 " : Indicates the Remote peer is sending " Null " (No) authentication.
Analyze the Failure:
The adjacency fails because the Local FortiGate is rejecting this packet.
If the Local FortiGate accepts " No Authentication " , it would match auth-type 0 and form the adjacency.
Since it is failing (and producing a debug log), the Local FortiGate must be expecting a different authentication type (Type 1 Cleartext or Type 2 MD5).
Evaluate the Options:
A). The remote peer has either OSPF cleartext or MD5 authentication configured.
Incorrect. The debug shows auth-type 0 (No Auth) coming from the remote peer.
B). There is an OSPF authentication configuration mismatch.
Correct. One side is sending " No Auth " (Remote), and the other expects " Auth " (Local). This is a definition of a mismatch.
C). The local FortiGate does not have OSPF authentication configured.
Incorrect. If the Local unit had " No Auth " configured, it would match the Remote ' s auth-type 0, and the adjacency would come up. The failure implies the Local unit does have auth configured.
D). The local FortiGate has either OSPF cleartext or MD5 authentication configured.
Correct. Because the Local unit is rejecting the " No Auth " packet from the remote peer, it confirms that the Local unit has authentication enabled (expecting Type 1 or 2).
Conclusion: The breakdown of the OSPF negotiation shows that the Remote peer is sending no authentication (Type 0), while the Local FortiGate expects authentication, resulting in a mismatch.
Reference:
FortiGate Security 7.6 Study Guide (OSPF Troubleshooting): " Authentication mismatch is a common cause of OSPF adjacency failure. Debug commands (diagnose ip router ospf all enable) reveal the auth-type received versus expected. " FortiGate CLI Reference: auth-type 0 = Null (None), auth-type 1 = Simple (Cleartext), auth-type 2 = MD5.