The answer is that state=bypass in the output of diagnose ips session list indicates the sessions are being offloaded to the NPU and are not inspected by IPS. This occurs because flow-based inspection allows the IPS engine to bypass sessions it deems low-risk or unnecessary to inspect, offloading them to the network processor to reduce CPU load and maintain throughput. On the Fortinet NSE 4 Network Security Professional NSE4 exam, this concept tests your understanding of how flow-based inspection differs from proxy-based inspection—a common trap is assuming bypass means a misconfiguration or failure, when it is actually normal, optimized behavior. Remember that in flow-based mode, bypass is a performance feature, not an error; the NPU handles these sessions without IPS scrutiny. A helpful memory tip: “Bypass means NPU pass—no IPS glass.”
NSE4 Security Profiles Practice Question
This NSE4 practice question tests your understanding of security profiles. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
A FortiGate is configured with flow-based inspection and an IPS profile. The administrator runs 'diagnose ips session list' and sees many sessions with 'state=bypass'. What does this indicate?
The IPS profile is configured with 'pass' action for all signatures
Why wrong: Pass action would still inspect but not block; the state would not be bypass.
B
The IPS signatures have expired and are not being applied
Why wrong: Expired signatures would not cause a bypass state; the engine would still try to inspect.
C
The FortiGate is under DoS attack and is dropping sessions
Why wrong: DoS attack might show drops, not bypass state.
D
The sessions are being offloaded to the NPU and are not inspected by IPS
In flow-based mode, many sessions are offloaded to NPU. The IPS engine marks them as 'bypass' because they are not sent to the CPU for inspection. This is expected behavior.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The sessions are being offloaded to the NPU and are not inspected by IPS
In flow-based IPS, sessions can be bypassed when the IPS engine determines that further inspection is unnecessary, for example, if the session is considered low-risk or to reduce CPU load. This is normal behavior in flow-based mode.
Key principle: NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
The IPS profile is configured with 'pass' action for all signatures
Why it's wrong here
Pass action would still inspect but not block; the state would not be bypass.
✗
The IPS signatures have expired and are not being applied
Why it's wrong here
Expired signatures would not cause a bypass state; the engine would still try to inspect.
✗
The FortiGate is under DoS attack and is dropping sessions
Why it's wrong here
DoS attack might show drops, not bypass state.
✓
The sessions are being offloaded to the NPU and are not inspected by IPS
Why this is correct
In flow-based mode, many sessions are offloaded to NPU. The IPS engine marks them as 'bypass' because they are not sent to the CPU for inspection. This is expected behavior.
Related concept
Static NAT maps one inside address to one outside address.
Common exam traps
Common exam trap: NAT rules depend on direction and matching traffic
NAT is not only about the public address. The inside/outside interface roles and the ACL or rule that matches traffic are just as important.
Trap categories for this question
Command / output trap
DoS attack might show drops, not bypass state.
Detailed technical explanation
How to think about this question
NAT questions usually test address translation, overload/PAT behaviour, static mappings and whether the right traffic is being translated. Read the interface direction and address terms carefully.
KKey Concepts to Remember
Static NAT maps one inside address to one outside address.
PAT allows many inside hosts to share one public address using ports.
Inside local and inside global describe the private and translated addresses.
NAT ACLs identify traffic for translation, not always security filtering.
TExam Day Tips
→Identify inside and outside interfaces first.
→Check whether the scenario needs static NAT, dynamic NAT or PAT.
→Do not confuse NAT matching ACLs with normal packet-filtering intent.
Key takeaway
NAT direction and interface roles matter as much as the IP address mapping. Inside/outside designation controls which traffic is translated.
Real-world example
How this comes up in practice
A small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.
What to study next
Got this wrong? Here's your next step.
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related NSE4 NAT questions on configuration and troubleshooting.
Security Profiles — This question tests Security Profiles — Static NAT maps one inside address to one outside address..
What is the correct answer to this question?
The correct answer is: The sessions are being offloaded to the NPU and are not inspected by IPS — In flow-based IPS, sessions can be bypassed when the IPS engine determines that further inspection is unnecessary, for example, if the session is considered low-risk or to reduce CPU load. This is normal behavior in flow-based mode.
What should I do if I get this NSE4 question wrong?
Review the four NAT address types (inside local, inside global, outside local, outside global), PAT port overload, and static vs dynamic NAT use cases. Then practise related NSE4 NAT questions on configuration and troubleshooting.
What is the key concept behind this question?
Static NAT maps one inside address to one outside address.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This NSE4 practice question is part of Courseiva's free Fortinet certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the NSE4 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.