The correct course of action is to add a firewall rule opening TCP port 8080 in the public zone using `firewall-cmd --add-port=8080/tcp --permanent` followed by a reload. This is necessary because the firewall’s public zone, by default, only permits traffic for explicitly allowed services like ssh (port 22) and http (port 80); since port 8080 is not listed, the firewall drops incoming packets to that port even though the application is listening on 0.0.0.0:8080 and is reachable at the network layer from both interfaces. On the Red Hat Certified System Administrator EX200 exam, this scenario tests your understanding of firewalld zone-based filtering and the distinction between allowing a service versus a raw port—a common trap is assuming that allowing the http service covers port 8080, when it only covers port 80. Remember the memory tip: “Services are shortcuts, ports are explicit”—if your app uses a non-standard port, you must open it directly with `--add-port`, not rely on a service name.
EX200 Deploy, configure, and maintain systems Practice Question
This EX200 practice question tests your understanding of deploy, configure, and maintain systems. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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 company has a RHEL 9 server that hosts a critical application. The server has two network interfaces: enp1s0 (192.168.1.100/24) and enp2s0 (10.0.0.100/24). The default gateway is 192.168.1.1. The application listens on a TCP port 8080 and should be accessible from both networks. Recently, the administrator noticed that clients on the 10.0.0.0/24 network can ping the server's 10.0.0.100 address but cannot connect to port 8080. Clients on 192.168.1.0/24 can connect fine. The firewall is configured with the default zone (public) and the service 'http' is allowed, but port 8080 is not specifically allowed. The administrator checks 'firewall-cmd --list-all' and sees that only services 'ssh' and 'http' are listed. The application is running and listening on 0.0.0.0:8080. What is the most likely cause and the correct course of action?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Add a firewall rule to open TCP port 8080 in the public zone using 'firewall-cmd --add-port=8080/tcp --permanent' and reload.
The firewall is blocking incoming connections to port 8080 because only services 'ssh' (port 22) and 'http' (port 80) are allowed in the public zone. Since the application listens on 0.0.0.0:8080, it is reachable from both networks at the IP level, but the firewall drops packets destined for port 8080. Adding a permanent rule to open TCP port 8080 and reloading the firewall configuration resolves the issue.
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.
✗
Disable SELinux to allow the application to accept connections.
Why it's wrong here
SELinux might block, but the likely issue is firewall; disabling SELinux is not best practice.
✓
Add a firewall rule to open TCP port 8080 in the public zone using 'firewall-cmd --add-port=8080/tcp --permanent' and reload.
Why this is correct
The firewall is blocking port 8080; adding the rule allows traffic.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
Change the application to listen only on the 10.0.0.100 interface.
Why it's wrong here
The application already listens on all interfaces; the issue is firewall.
✗
Add a static route for the 10.0.0.0/24 network via the 10.0.0.1 gateway.
Why it's wrong here
Routing is not the issue; clients can ping.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates assume the application is unreachable due to a routing or SELinux issue, overlooking the fact that the firewall's default zone only allows explicitly listed services and ports, and that 'http' does not cover port 8080.
Detailed technical explanation
How to think about this question
The default firewall zone in RHEL 9 is 'public', which applies to all interfaces unless overridden. The 'firewall-cmd --add-port=8080/tcp --permanent' command adds a direct port rule to the nftables or iptables backend, and '--reload' applies the change without restarting the service. In a real-world scenario, administrators often confuse service names (e.g., 'http' for port 80) with custom ports, leading to connectivity issues when applications use non-standard ports like 8080.
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 practitioner preparing for the EX200 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
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.
Deploy, configure, and maintain systems — This question tests Deploy, configure, and maintain systems — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Add a firewall rule to open TCP port 8080 in the public zone using 'firewall-cmd --add-port=8080/tcp --permanent' and reload. — The firewall is blocking incoming connections to port 8080 because only services 'ssh' (port 22) and 'http' (port 80) are allowed in the public zone. Since the application listens on 0.0.0.0:8080, it is reachable from both networks at the IP level, but the firewall drops packets destined for port 8080. Adding a permanent rule to open TCP port 8080 and reloading the firewall configuration resolves the issue.
What should I do if I get this EX200 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: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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 →
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 EX200 practice question is part of Courseiva's free Red Hat 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 EX200 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.