CND Practice Question: Network Security Controls Protocols And Devices
A network security analyst is reviewing NetFlow records and notices an unusually high volume of small UDP packets originating from a single internal host destined to various random external IP addresses on ephemeral ports. What type of network attack or anomaly does this signature indicate?
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
UDP flood Denial of Service attack
A high volume of small UDP packets sent to random high ports indicates a UDP flood Denial of Service (DoS) attack originating from the compromised internal host.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
ARP cache poisoning spoofing attack
Why it's wrong here
ARP spoofing occurs entirely at Layer 2 on the local broadcast domain, not via external UDP packet transmissions.
- ✓
UDP flood Denial of Service attack
Why this is correct
Flooding random external ports with UDP packets is characteristic of a UDP flood attack.
- ✗
TCP SYN flood attack against internal servers
Why it's wrong here
SYN floods involve TCP packets with the SYN flag set, targeting TCP handshake states, not random UDP packets.
- ✗
DNS zone transfer enumeration (AXFR)
Why it's wrong here
DNS zone transfers typically use TCP port 53, not arbitrary external UDP ephemeral ports.
About these practice questions
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed August 2026 · checked against the official EC-Council exam blueprint
This CND practice question is part of Courseiva's free EC-Council certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the CND exam.