The answer is that DHCP snooping is not enabled, so DAI lacks the DHCP snooping binding table. Dynamic ARP Inspection depends on DHCP snooping because it uses the binding table—a database of valid MAC-to-IP address mappings—to validate ARP packets on untrusted ports. Without DHCP snooping active, the binding table remains empty, causing DAI to drop all ARP packets, including the DHCP discovery and request messages that hosts need to obtain IP addresses. On the Cisco DCCOR 350-601 exam, this dependency is a frequent trap: candidates often enable DAI but forget that it is a security feature built upon DHCP snooping, not a standalone function. The exam tests your understanding that DAI is only as effective as the binding table that feeds it. A simple memory tip is “No Snoop, No Table, No DAI”—if DHCP snooping is off, the binding table is empty, and DAI will block all ARP traffic, breaking DHCP.
350-601 Security Practice Question
This 350-601 practice question tests your understanding of security. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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.
An organization is deploying Cisco Nexus 9000 switches with NX-OS and needs to prevent ARP spoofing attacks. The network engineer enables Dynamic ARP Inspection (DAI) on all VLANs. However, some legitimate hosts are unable to obtain IP addresses via DHCP. What is the most likely reason?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
DHCP snooping is not enabled, so DAI lacks the DHCP snooping binding table.
DAI relies on the DHCP snooping binding table to validate ARP packets. Without DHCP snooping enabled, the binding table is empty, so DAI cannot determine which ARP packets are legitimate, causing it to drop all ARP packets, including DHCP discovery and request messages. This prevents hosts from obtaining IP addresses via DHCP.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
The ARP rate limit on the port is too low, causing all ARP requests to be dropped.
Why it's wrong here
Rate limiting drops excessive ARPs but does not block all.
✗
IP Source Guard is enabled and is blocking ARP packets.
Why it's wrong here
IP Source Guard blocks IP traffic, not ARP, and is separate from DAI.
✓
DHCP snooping is not enabled, so DAI lacks the DHCP snooping binding table.
Why this is correct
DAI validates ARP against DHCP snooping database; without it, DAI drops all ARP on untrusted ports.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
An ARP ACL is not configured to allow static IP bindings.
Why it's wrong here
ARP ACLs are not required for DAI to work with DHCP.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the dependency of DAI on DHCP snooping, and the trap here is that candidates assume DAI can function independently without understanding that it requires the DHCP snooping binding table for validation.
Detailed technical explanation
How to think about this question
DAI intercepts all ARP packets on untrusted ports and validates them against the DHCP snooping binding table, which maps IP addresses to MAC addresses and switch ports. If DHCP snooping is not enabled, the binding table is empty, causing DAI to drop all ARP packets as invalid. In a real-world scenario, this often occurs when administrators enable DAI globally but forget to enable DHCP snooping, leading to complete loss of DHCP service on the VLAN.
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 help-desk technician troubleshoots why a newly connected PC cannot reach shared printers on the same floor. The cable is good, the switch port is active, but the PC is in VLAN 20 and the printers are in VLAN 10. The uplink trunk only allows VLAN 10. A trunk being up does not mean every VLAN crosses it.
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.
Security — This question tests Security — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: DHCP snooping is not enabled, so DAI lacks the DHCP snooping binding table. — DAI relies on the DHCP snooping binding table to validate ARP packets. Without DHCP snooping enabled, the binding table is empty, so DAI cannot determine which ARP packets are legitimate, causing it to drop all ARP packets, including DHCP discovery and request messages. This prevents hosts from obtaining IP addresses via DHCP.
What should I do if I get this 350-601 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
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 →
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.
This 350-601 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 350-601 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.