Question 1mediummultiple choice
Full question →mediummultiple choiceObjective-mapped
A network technician is troubleshooting a user's inability to access a specific internal web application hosted on a server at 10.10.10.15:8080. The user can ping the server's IP address successfully, but the web browser displays 'connection refused'. The technician verifies that the web application service is running on the server. What is the most likely cause of the issue?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Best answer
The server's firewall is blocking inbound connections to port 8080.
Connection refused often indicates that a firewall is blocking the specific port. Since the server is reachable via ping, the issue is at the port level. Checking the server firewall rules for port 8080 is the next step.
B
Distractor review
The web application is listening on a different port than 8080.
The technician verified the service is running, but if it were on a different port, the connection would still be refused. However, the most likely first cause to check is the firewall. Also, the question says 'connection refused', which is a response from the server, not a timeout; if the service were on a different port, the firewall might still allow the connection but the service wouldn't respond; depending on configuration, this could also give 'connection refused' if the port is closed. But firewall is more common.
C
Distractor review
The user's web browser is configured to use an incorrect proxy server.
A proxy misconfiguration would typically result in a proxy error message (e.g., 'proxy server not responding') rather than 'connection refused' directly to the server IP.
D
Distractor review
The DNS resolution is failing for the server's hostname.
The user is accessing the server via IP address (10.10.10.15), so DNS is not involved. Ping to the IP succeeded, so network connectivity is fine.
Common exam trap
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.
Technical deep dive
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.
Related practice questions
Related N10-009 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Network+ network fundamentals practice questions
Practise N10-009 questions linked to Network+ network fundamentals.
Network+ implementation practice questions
Practise N10-009 questions linked to Network+ implementation.
Network+ operations practice questions
Practise N10-009 questions linked to Network+ operations.
Network+ security practice questions
Practise N10-009 questions linked to Network+ security.
Network+ troubleshooting practice questions
Practise N10-009 questions linked to Network+ troubleshooting.
More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A network engineer needs to connect two switches located 400 meters apart. The cable run includes high electromagnetic interference from nearby machinery. The engineer decides to use fiber optic cabling. Which transceiver type and fiber combination should be used to ensure the link reaches 400 meters while remaining cost-effective?
Question 2
A network engineer is designing a new switched network and needs to ensure that broadcast traffic from one department does not reach another department's workstations. The engineer plans to use VLANs. Which of the following must be configured on the switches to isolate broadcast domains as intended?
Question 3
A security engineer is configuring a site-to-site VPN between two branch offices. The requirement is to encrypt all traffic between the two networks using IPsec. Which IPsec mode should be used to encrypt the entire IP packet including the original header?
Question 4
A network administrator is connecting two switches to increase bandwidth and provide redundancy. Which technology should be used to combine multiple physical links into a single logical link?
Question 5
A network administrator is experiencing issues where unauthorized devices are offering IP addresses to clients, causing connectivity problems. Which security feature should be enabled on switches to prevent this?
Question 6
A network administrator is troubleshooting a connectivity issue and suspects the problem is related to the physical cabling. At which layer of the OSI model should the administrator begin their investigation?
FAQ
Questions learners often ask
What does this N10-009 question test?
Static NAT maps one inside address to one outside address.
What is the correct answer to this question?
The correct answer is: The server's firewall is blocking inbound connections to port 8080. — Connection refused typically means that the destination port is not open or a firewall is blocking the connection. Since the server is reachable via ping (ICMP), the issue is likely at Layer 4 (Transport). The firewall on the server or a network firewall might be blocking port 8080. The service is running, so it's not a server down issue. Proxy misconfiguration could cause issues but would typically give a different error (e.g., proxy error). DNS is not relevant since the IP is used.
What should I do if I get this N10-009 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
Discussion
Loading comments…
Sign in to join the discussion.