mediummultiple choiceObjective-mapped

A public-facing web service suddenly becomes very slow. NetFlow shows a high volume of small DNS queries leaving attacker-controlled systems and much larger DNS responses arriving at the victim's IP address from many different resolvers. Which attack is taking place?

Question 1mediummultiple choice
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A public-facing web service suddenly becomes very slow. NetFlow shows a high volume of small DNS queries leaving attacker-controlled systems and much larger DNS responses arriving at the victim's IP address from many different resolvers. Which attack is taking place?

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

DNS amplification DDoS

DNS amplification uses small spoofed queries to elicit much larger responses toward the victim.

B

Distractor review

Replay attack

A replay attack reuses captured valid traffic, which does not explain the response-heavy flood pattern.

C

Distractor review

ARP poisoning

ARP poisoning affects local network address resolution and would not generate distributed DNS responses.

D

Distractor review

Session fixation

Session fixation manipulates a web session identifier, not bandwidth through reflective DNS traffic.

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 SY0-701 practice-question pages

Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.

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.

FAQ

Questions learners often ask

What does this SY0-701 question test?

Static NAT maps one inside address to one outside address.

What is the correct answer to this question?

The correct answer is: DNS amplification DDoS — This is a DNS amplification distributed denial-of-service attack. The attacker sends small queries, often with a spoofed source address, to open resolvers that generate much larger responses toward the victim. The result is high bandwidth consumption and service degradation without requiring the attacker to send equally large amounts of traffic directly. The clue about many different resolvers and much larger responses is the key indicator of reflection and amplification rather than a direct flood. Why others are wrong: A replay attack would involve resubmitting previously captured legitimate packets or tokens, not abusing third-party DNS resolvers. ARP poisoning is confined to local LAN address mapping and would not create traffic from many resolvers across the internet. Session fixation targets authentication state in web applications and has nothing to do with the response amplification pattern shown in the netflow data.

What should I do if I get this SY0-701 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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