Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
A security analyst is investigating a potential data exfiltration. The analyst notices that a server is sending DNS queries to an external IP address on TCP port 53, and the DNS responses are unusually large. The server is not a DNS server. Which technique is most likely being used?
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
Distractor review
DNS amplification attack
DNS amplification is a DDoS technique where an attacker sends small queries with spoofed IPs to generate large responses; here the server is sending queries to an external IP, and it's sending queries, not receiving them with spoofed source.
B
Best answer
DNS tunneling
DNS tunneling uses DNS protocol to encapsulate other data, often for command-and-control or data exfiltration. Large response sizes and unusual use of TCP port 53 are indicators.
C
Distractor review
DNS zone transfer
A zone transfer is a legitimate DNS replication mechanism between authoritative servers; it uses TCP port 53 but is not used for data exfiltration from a non-DNS server.
D
Distractor review
DNS cache poisoning
DNS cache poising involves inserting false records into a DNS resolver's cache; it does not involve a server sending many queries or large responses for exfiltration.
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: DNS tunneling — DNS tunneling encapsulates non-DNS data (e.g., stolen data) inside DNS queries and responses. Using TCP port 53 instead of UDP is common for tunneling because TCP can handle larger payloads. The large DNS responses indicate data exfiltration via the response payload. DNS amplification is a DDoS attack that uses small queries to generate large responses, but the server is initiating queries, not receiving them. Zone transfer would occur between DNS servers. DNS cache poisoning involves corrupting resolver cache, not exfiltration.
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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