The answer is that IPv4 extended access lists are typically placed as close to the source as possible. This is correct because extended ACLs evaluate traffic based on source and destination IP addresses, protocol type, and port numbers, allowing them to filter unwanted traffic early in the path and conserve bandwidth. On the Cisco CCNP ENARSI 300-410 exam, this principle tests your understanding of ACL placement strategy: extended lists filter with granularity, so placing them near the source prevents malicious or unnecessary traffic from traversing the network, unlike standard ACLs which are placed near the destination. A common trap is confusing this with standard ACL placement—remember, extended ACLs are source-close, standard ACLs are destination-close. For a memory tip, think “Extended = Early” to recall that extended lists should be applied as close to the traffic source as possible.
300-410 IPv4 Access Control Lists Practice Question
This 300-410 practice question tests your understanding of ipv4 access control lists. 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 TWO statements about IPv4 extended access control lists are true? (Choose TWO.)
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
They can filter based on source and destination IP addresses.
Option A is correct because IPv4 extended ACLs can filter traffic based on both source and destination IP addresses, as well as protocol type, port numbers, and other parameters. This is defined in the access-list command syntax (e.g., access-list 100 permit tcp 10.0.0.0 0.255.255.255 192.168.1.0 0.0.0.255 eq 80), which allows granular control beyond standard ACLs that only filter on source IP.
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.
✓
They can filter based on source and destination IP addresses.
Why this is correct
Extended ACLs can specify both source and destination addresses in the permit/deny statement.
Related concept
Read the scenario before looking for a memorised answer.
✓
They are typically placed as close to the source as possible.
Why this is correct
Best practice for extended ACLs is to apply them near the source to conserve bandwidth.
Related concept
Read the scenario before looking for a memorised answer.
✗
They use a wildcard mask only for the destination address.
Why it's wrong here
Wildcard masks are used for both source and destination addresses in extended ACLs.
✗
They can be named using numbers only.
Why it's wrong here
Numbered ACLs use numbers; named ACLs use alphanumeric names.
✗
They automatically log all matched packets.
Why it's wrong here
Logging requires the 'log' keyword; it is not automatic.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Cisco often tests the misconception that extended ACLs can only be numbered, but they support named ACLs as well, and that wildcard masks apply only to one address field, whereas they apply to both source and destination.
Trap categories for this question
Keyword trap
Logging requires the 'log' keyword; it is not automatic.
Detailed technical explanation
How to think about this question
Extended ACLs are processed top-down, and the first match determines the action (permit or deny); an implicit deny any any exists at the end. In real-world scenarios, placing extended ACLs close to the source (Option B) reduces unnecessary traffic across the network, but this is a best practice for standard ACLs; for extended ACLs, it is also recommended but not always possible due to policy requirements. The wildcard mask uses 0 to match exactly and 1 to ignore bits, allowing flexible subnet matching.
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: They can filter based on source and destination IP addresses. — Option A is correct because IPv4 extended ACLs can filter traffic based on both source and destination IP addresses, as well as protocol type, port numbers, and other parameters. This is defined in the access-list command syntax (e.g., access-list 100 permit tcp 10.0.0.0 0.255.255.255 192.168.1.0 0.0.0.255 eq 80), which allows granular control beyond standard ACLs that only filter on source IP.
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.