The correct approach is to identify the application signature for Skype for Business and then block all other Skype-related application signatures. This works because FortiGate’s application control engine uses predefined signatures to differentiate between Skype variants; by explicitly allowing the Skype for Business signature and blocking the rest, you enforce a strict allowlist without needing custom signatures. On the Fortinet NSE 4 exam, this scenario tests your understanding of application control profiles and signature-based filtering, often appearing as a multiple-select question where common traps include choosing “create a custom signature” or “enable logging on all traffic” as unnecessary steps. A key memory tip is to think of it as “allow one, block the rest” — the signatures already exist, so you simply toggle the action for each Skype variant rather than reinventing the wheel.
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 an application control profile to allow only 'business-approved' applications. Users are still able to use Skype for Business. The admin wants to ensure that only Skype for Business is allowed and other Skype variants are blocked. Which THREE steps should the admin take? (Choose three.)
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Identify the exact application signatures for Skype for Business
Options A, C, and D are correct. The admin should identify the correct application signature for Skype for Business and block other Skype signatures. Creating a custom signature is not necessary as the signatures already exist. Logging all traffic is not directly needed for blocking.
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.
✓
Identify the exact application signatures for Skype for Business
Why this is correct
Needed to allow only the correct application.
Related concept
Static NAT maps one inside address to one outside address.
✓
Apply the application control profile to the firewall policy
Why this is correct
The profile must be applied to the policy to take effect.
Related concept
Static NAT maps one inside address to one outside address.
✗
Enable logging for all traffic to verify the application being used
Why it's wrong here
Logging is helpful but not a step required to achieve the blocking; it's for verification.
✗
Create a custom application signature for Skype for Business
Why it's wrong here
Custom signatures are not needed; predefined signatures exist.
✓
Block all other Skype-related application signatures
Why this is correct
To prevent other Skype variants, block their signatures.
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.
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: Identify the exact application signatures for Skype for Business — Options A, C, and D are correct. The admin should identify the correct application signature for Skype for Business and block other Skype signatures. Creating a custom signature is not necessary as the signatures already exist. Logging all traffic is not directly needed for blocking.
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.