- A
Allow inbound HTTP/HTTPS to web server; allow web server to database on port 3306; deny all else
This permits necessary traffic and restricts database access to only the web server.
- B
Allow web server to initiate outbound connections to internet; allow database to initiate connections to web server; deny all else
Why wrong: This does not allow inbound web traffic from the internet.
- C
Allow inbound HTTP/HTTPS to web server; allow all traffic from web server to database; deny all else
Why wrong: Allowing all traffic from web server to database is too broad; only specific ports should be allowed.
- D
Allow inbound HTTP/HTTPS to web server; allow inbound SQL from internet to database; deny all else
Why wrong: This exposes the database to the internet, which is insecure.
Quick Answer
The correct answer is the rule set that allows inbound HTTP/HTTPS to the web server, permits the web server to connect to the database on port 3306, and denies all else. This configuration is correct because it strictly enforces the principle of least privilege within a DMZ: the database server is isolated from direct internet access, with only the web server authorized to initiate traffic to it on the default MySQL/MariaDB port, thereby minimizing the attack surface while supporting the required application flow. On the ISC2 Certified in Cybersecurity CC exam, this scenario tests your understanding of DMZ segmentation and layered defense, often appearing as a trick where a distractor allows direct inbound access to the database or permits all traffic from the web server. A common trap is assuming the database needs its own inbound rule from the internet; remember that in a proper DMZ, the database should never be reachable from outside. Memory tip: think “web in, DB out” — only the web server talks to the database, and only on the specific port needed.
ISC2 CC Network Security Practice Question
This CC practice question tests your understanding of network security. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. 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 network administrator is designing a DMZ to host a public-facing web server and a database server that should only be accessible from the web server. Which of the following firewall rule sets best achieves this design?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue:
"best"Why it matters: Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Allow inbound HTTP/HTTPS to web server; allow web server to database on port 3306; deny all else
Option A is correct because it implements the principle of least privilege for a DMZ: it allows inbound HTTP/HTTPS traffic (ports 80/443) to the public-facing web server, then permits only the web server to initiate outbound connections to the database server on port 3306 (MySQL/MariaDB default), and denies all other traffic. This ensures the database is not directly accessible from the internet, reducing the attack surface while still supporting the required application flow.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Allow inbound HTTP/HTTPS to web server; allow web server to database on port 3306; deny all else
Why this is correct
This permits necessary traffic and restricts database access to only the web server.
Clue confirmation
The clue word "best" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
- ✗
Allow web server to initiate outbound connections to internet; allow database to initiate connections to web server; deny all else
Why it's wrong here
This does not allow inbound web traffic from the internet.
- ✗
Allow inbound HTTP/HTTPS to web server; allow all traffic from web server to database; deny all else
Why it's wrong here
Allowing all traffic from web server to database is too broad; only specific ports should be allowed.
- ✗
Allow inbound HTTP/HTTPS to web server; allow inbound SQL from internet to database; deny all else
Why it's wrong here
This exposes the database to the internet, which is insecure.
Common exam traps
Common exam trap: answer the scenario, not the keyword
ISC2 often tests the principle of least privilege by including options that allow overly broad access (like 'all traffic' from web to database) or reverse the direction of connections, so the trap here is assuming that any traffic between the web server and database is acceptable without specifying the exact protocol and port.
Detailed technical explanation
How to think about this question
In a typical DMZ architecture, the web server resides in a separate subnet with firewall rules that permit only necessary traffic: inbound HTTP/HTTPS from the internet, and outbound SQL (port 3306) to the database server in a more restricted internal zone. The firewall should also enforce stateful inspection to ensure that only established sessions from the web server to the database are allowed, preventing spoofed or unsolicited traffic. In real-world scenarios, additional hardening might include using non-default ports, TLS encryption for database connections, and application-layer filtering to prevent SQL injection.
KKey Concepts to Remember
- Read the scenario before looking for a memorised answer.
- Find the constraint that changes the correct option.
- Eliminate answers that are true in general but not in this case.
TExam Day Tips
- Watch for words such as best, first, most likely and least administrative effort.
- Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A security analyst at a medium-sized enterprise encounters this scenario during an investigation or architecture review. The correct answer reflects best practice for the specific threat or control described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Security exam questions test whether you can match controls to threats in context — not just recall definitions.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
Network Security — study guide chapter
Learn the concepts, then practise the questions
- →
Network Security practice questions
Targeted practice on this topic area only
- →
All CC questions
500 questions across all exam domains
- →
ISC2 Certified in Cybersecurity CC study guide
Full concept coverage aligned to exam objectives
- →
CC practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related CC practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Access Controls Concepts practice questions
Practise CC questions linked to Access Controls Concepts.
Business Continuity, DR & Incident Response practice questions
Practise CC questions linked to Business Continuity, DR & Incident Response.
Security Principles practice questions
Practise CC questions linked to Security Principles.
Network Security practice questions
Practise CC questions linked to Network Security.
Security Operations practice questions
Practise CC questions linked to Security Operations.
CC fundamentals practice questions
Practise CC questions linked to CC fundamentals.
CC scenario practice questions
Practise CC questions linked to CC scenario.
CC troubleshooting practice questions
Practise CC questions linked to CC troubleshooting.
Practice this exam
Start a free CC practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this CC question test?
Network Security — This question tests Network Security — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Allow inbound HTTP/HTTPS to web server; allow web server to database on port 3306; deny all else — Option A is correct because it implements the principle of least privilege for a DMZ: it allows inbound HTTP/HTTPS traffic (ports 80/443) to the public-facing web server, then permits only the web server to initiate outbound connections to the database server on port 3306 (MySQL/MariaDB default), and denies all other traffic. This ensures the database is not directly accessible from the internet, reducing the attack surface while still supporting the required application flow.
What should I do if I get this CC question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "best". Signals that multiple options may be partially correct. Choose the option that most directly solves the exact problem described, not the one that sounds most complete.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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 →
Last reviewed: Jun 30, 2026
This CC practice question is part of Courseiva's free ISC2 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 CC 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.