Free N10-009 sample questions with answers
Try these before reading the answers. The mix follows the weighting, so troubleshooting and concepts appear most.
Question 1. A user can reach websites by IP address but not by name. Other users on the same subnet are unaffected. Which is the most likely cause?
- A. The default gateway has failed
- B. The patch cable to the workstation is faulty
- C. The workstation’s DNS configuration is incorrect
- D. A duplex mismatch on the switch port
Show answer
Answer: C
Reaching hosts by IP but not by name isolates the fault to name resolution, and the problem affecting only one user points to that workstation’s DNS configuration. A failed default gateway would prevent IP connectivity too, a faulty cable would break everything, and a duplex mismatch degrades performance rather than selectively breaking name lookup.
Question 2. A host is configured with 192.168.10.75/26. What is the broadcast address of its subnet?
- A. 192.168.10.63
- B. 192.168.10.127
- C. 192.168.10.191
- D. 192.168.10.255
Show answer
Answer: B
A /26 gives 64 addresses per subnet, so the boundaries are .0, .64, .128 and .192; 75 falls in the .64 subnet, whose broadcast address is .127. The other options correspond to different subnet boundaries or to a /24 network.
Question 3. Following CompTIA's troubleshooting methodology, what comes immediately after establishing a theory of probable cause?
- A. Implement the solution
- B. Document findings, actions and outcomes
- C. Escalate to a senior engineer
- D. Test the theory to determine the cause
Show answer
Answer: D
The methodology moves from establishing a theory to testing that theory to determine the cause, and only then to establishing a plan of action. Implementing a solution or documenting findings both come later, and escalation is not the defined next step.
Question 4. Wireless users in one area of an office report intermittent drops. A site survey shows three nearby access points all broadcasting on 2.4 GHz channel 6. What should be changed?
- A. Assign non-overlapping channels such as 1, 6 and 11 to the access points
- B. Increase transmit power on all three access points
- C. Replace the Ethernet cabling to the access points
- D. Extend the DHCP lease duration on the wireless scope
Show answer
Answer: A
Overlapping access points on the same 2.4 GHz channel interfere with one another, and assigning non-overlapping channels such as 1, 6 and 11 resolves it. Increasing transmit power worsens co-channel interference, replacing cabling does not affect radio conditions, and a longer DHCP lease is unrelated.
Question 5. A network segment must be isolated so that its traffic cannot reach the finance servers, without installing additional physical switches. What should be implemented?
- A. A longer DHCP lease on the segment
- B. VLAN segmentation with controlled routing between VLANs
- C. A stronger wireless passphrase
- D. A faster uplink to the core switch
Show answer
Answer: B
VLANs separate traffic logically on existing switch hardware, with routing controls determining what may cross between them, which meets the isolation requirement without new equipment. A longer DHCP lease, a stronger wireless passphrase and a faster uplink do not provide segmentation.
How did you do?
Question 2 is the one to pay attention to. Subnetting appears throughout the exam, not just in the concepts domain, and it is the skill that most reliably separates prepared candidates from unprepared ones. If it took you more than a minute, start the daily practice described in the study plan.
Question 3 is also worth noting: the troubleshooting methodology is examined in order, and “what comes next” questions are answered by knowing the sequence.