A technician is troubleshooting a connectivity issue. The technician can successfully ping the IP address of a web server (10.10.10.10) from a client, but the client cannot access the web page. Firewall rules allow HTTP traffic. At which OSI layer is the issue most likely occurring?
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.
Best answer
Application layer (Layer 7)
Correct. The web service (HTTP) is an Application layer protocol. If the service is not running or misconfigured, the client cannot access the web page despite lower-layer connectivity.
Distractor review
Session layer (Layer 5)
The Session layer manages sessions, but HTTP is an Application layer protocol. Session issues are less likely given successful lower-layer communication.
Distractor review
Transport layer (Layer 4)
Since the firewall allows HTTP traffic, a Transport layer block is unlikely. If it were a port issue, ping would still work, but the symptom would be consistent with a firewall block. However, the most likely cause is the Application layer.
Distractor review
Network layer (Layer 3)
Successful ping confirms that the Network layer (IP addressing and routing) is functioning correctly. The problem is at a higher layer.
Common exam trap
Common exam trap: answer the scenario, not the keyword
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Technical deep dive
How to think about this question
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
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.
- Use explanations to understand the rule behind the answer.
TExam Day Tips
- Underline the problem statement mentally.
- 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.
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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?
Read the scenario before looking for a memorised answer.
What is the correct answer to this question?
The correct answer is: Application layer (Layer 7) — Ping operates at the Network layer (Layer 3) using ICMP. Since pinging the IP address succeeds, the Network layer, Data Link layer, and Physical layer are functioning correctly. The failure to access a web page (HTTP) suggests a problem at the Application layer (Layer 7), such as the web service not running on the server, or at the Transport layer (Layer 4) if the firewall is blocking the specific port. However, the question states firewall allows HTTP, so the most likely cause is the Application layer (e.g., web server service down).
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.
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