The answer is that standard ACLs should be placed closest to the destination when filtering traffic between two internal subnets. This is correct because standard ACLs evaluate traffic based solely on the source IP address, lacking the ability to distinguish between different destination subnets. Placing a standard ACL near the destination ensures it only filters traffic that has already reached the target subnet, preventing it from inadvertently blocking traffic destined for other networks that share the same source. On the Cisco CCNP ENARSI 300-410 exam, this concept tests your understanding of ACL placement best practice, often appearing in questions about traffic filtering efficiency and unintended denial of service. A common trap is assuming standard ACLs can be placed anywhere like extended ACLs, but remember: extended ACLs filter on source and destination, so they go near the source to block early, while standard ACLs go near the destination to avoid over-blocking. Memory tip: “Standard Stays near the Destination, Extended Exits near the Source.”
300-410 IPv4 Access Control Lists Practice Question
This 300-410 practice question tests your understanding of ipv4 access control lists. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. 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 of the following is true regarding the placement of an IPv4 ACL to filter traffic between two internal subnets?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Standard ACLs should be placed closest to the destination.
Standard ACLs filter based solely on the source IP address and lack the granularity to distinguish between different destination subnets. Placing a standard ACL closest to the destination ensures that traffic is filtered only after it has reached the target subnet, preventing the ACL from inadvertently blocking traffic to other destinations that share the same source. This placement aligns with the Cisco best practice of placing standard ACLs near the destination to minimize unintended filtering.
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.
✗
Standard ACLs should be placed closest to the source.
Why it's wrong here
Standard ACLs filter only on source IP, so placing near destination avoids filtering unintended traffic.
✗
Extended ACLs should be placed closest to the destination.
Why it's wrong here
Extended ACLs filter on source and destination; placing near source saves bandwidth.
✓
Standard ACLs should be placed closest to the destination.
Why this is correct
Standard ACLs lack destination filtering; placing near destination prevents blocking traffic to other networks.
Related concept
Read the scenario before looking for a memorised answer.
✗
Placement does not affect ACL functionality.
Why it's wrong here
Placement is critical for effective filtering and performance.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the misconception that standard ACLs should be placed closest to the source (like extended ACLs), but the correct practice is to place standard ACLs closest to the destination due to their lack of destination-based filtering.
Detailed technical explanation
How to think about this question
Standard ACLs (numbered 1-99 or 1300-1999) evaluate only the source IP address, so placing them near the source can block all traffic from that source, even to legitimate destinations. In contrast, extended ACLs (numbered 100-199 or 2000-2699) can match source, destination, protocol, and port, allowing precise filtering near the source to drop unwanted traffic early. A real-world scenario is filtering traffic between two internal VLANs: a standard ACL applied inbound on the destination router interface ensures only traffic destined for that specific subnet is evaluated, avoiding disruption to other subnets.
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 small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this 300-410 question in full detail.
IPv4 Access Control Lists — This question tests IPv4 Access Control Lists — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Standard ACLs should be placed closest to the destination. — Standard ACLs filter based solely on the source IP address and lack the granularity to distinguish between different destination subnets. Placing a standard ACL closest to the destination ensures that traffic is filtered only after it has reached the target subnet, preventing the ACL from inadvertently blocking traffic to other destinations that share the same source. This placement aligns with the Cisco best practice of placing standard ACLs near the destination to minimize unintended filtering.
What should I do if I get this 300-410 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 →
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 300-410 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 300-410 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.