Question 1mediummulti select
Full question →Question 1,305 of 1,819
Quick Answer
The correct answer identifies that Dynamic ARP Inspection (DAI) validates ARP packets by intercepting them on untrusted ports and checking the MAC-to-IP address binding against the DHCP snooping binding database. This validation process is why DAI drops any ARP packet with an invalid or missing binding, effectively preventing ARP spoofing and man-in-the-middle attacks at Layer 2. On the CCNA 200-301 v2 exam, this topic tests your understanding of how DAI relies entirely on the DHCP snooping database as its source of truth, and a common trap is assuming DAI can operate without DHCP snooping being enabled first. Remember that DAI is always configured on untrusted ports facing end hosts, while trusted ports (typically uplinks to other switches) are exempt from inspection. A useful memory tip is "DAI Drops ARP on Untrusted Ports" — think of DAI as the security guard that checks every ARP packet's ID against the DHCP snooping guest list before letting it through.
CCNA Network Services and Security Practice Question
This 200-301 practice question tests your understanding of network services and security. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Which three options are true regarding the operation of Dynamic ARP Inspection (DAI) on a Cisco switch? (Choose three.)
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
✓
DAI validates ARP packets based on the DHCP snooping binding database.
Dynamic ARP Inspection (DAI) validates ARP packets by intercepting them on untrusted ports and checking the MAC-to-IP address binding against the DHCP snooping binding database. If the binding is invalid or missing, DAI drops the packet, preventing ARP spoofing attacks. This is why all three statements are correct: DAI relies on the DHCP snooping database, drops invalid bindings, and is enabled on untrusted ports facing end hosts.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the misconception that DAI validates ARP packets using the MAC address table or ARP cache, when in fact it strictly relies on the DHCP snooping binding database.
Detailed technical explanation
How to think about this question
DAI uses the DHCP snooping binding table as its source of truth; if DHCP snooping is not enabled, DAI cannot validate ARP packets and will drop all ARP traffic on untrusted ports by default. DAI also supports ARP ACLs for static bindings and rate limiting to prevent DoS attacks. In a real-world scenario, a misconfigured DAI on a trunk port (which should be trusted) can cause legitimate ARP traffic to be dropped, leading to connectivity loss.
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.
TExam Day Tips
- 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.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the 200-301 exam encounters this exact type of scenario on the job. The correct answer here is not the most general option — it is the best answer for the specific constraint described. Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option. Real exam questions reward reading the full scenario before eliminating options, because the constraint defines which answer fits.
What to study next
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
- →
Network Services and Security — study guide chapter
Learn the concepts, then practise the questions
- →
Network Services and Security practice questions
Targeted practice on this topic area only
- →
All 200-301 questions
1,819 questions across all exam domains
- →
CCNA 200-301 v2 study guide
Full concept coverage aligned to exam objectives
- →
200-301 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related 200-301 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Network Infrastructure and Connectivity practice questions
Practise 200-301 questions linked to Network Infrastructure and Connectivity.
Switching and Network Access practice questions
Practise 200-301 questions linked to Switching and Network Access.
IP Routing practice questions
Practise 200-301 questions linked to IP Routing.
Network Services and Security practice questions
Practise 200-301 questions linked to Network Services and Security.
AI and Network Operations practice questions
Practise 200-301 questions linked to AI and Network Operations.
CCNA subnetting practice questions
Practise IPv4 subnetting, CIDR, masks, host ranges and subnet selection.
CCNA OSPF practice questions
Practise OSPF neighbours, router IDs, metrics, areas and routing-table interpretation.
CCNA VLAN practice questions
Practise VLANs, access ports, trunks, allowed VLANs and switching scenarios.
CCNA STP practice questions
Practise spanning tree, root bridge election, port roles and STP troubleshooting.
CCNA EtherChannel practice questions
Practise LACP, PAgP, port-channel behaviour and bundle requirements.
CCNA ACL practice questions
Practise standard and extended ACLs, permit/deny logic and traffic filtering.
CCNA NAT practice questions
Practise static NAT, dynamic NAT, PAT and inside/outside address translation.
Practice this exam
Start a free 200-301 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this 200-301 question test?
Network Services and Security — This question tests Network Services and Security — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: DAI validates ARP packets based on the DHCP snooping binding database. — Dynamic ARP Inspection (DAI) validates ARP packets by intercepting them on untrusted ports and checking the MAC-to-IP address binding against the DHCP snooping binding database. If the binding is invalid or missing, DAI drops the packet, preventing ARP spoofing attacks. This is why all three statements are correct: DAI relies on the DHCP snooping database, drops invalid bindings, and is enabled on untrusted ports facing end hosts.
What should I do if I get this 200-301 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
Last reviewed: Jun 11, 2026
This 200-301 practice question is part of Courseiva's free Cisco 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 200-301 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.