Quick Answer
The answer is DHCPv6 Option 23, the DNS Recursive Name Server option. This option is correct because it carries the list of DNS server addresses that DHCPv6 clients use for name resolution, as defined in RFC 3646. When a client requests network configuration, the DHCPv6 server includes Option 23 to provide one or more IPv6 addresses of recursive name servers, enabling the client to resolve domain names without needing to manually configure DNS. On the Cisco CCNP ENARSI 300-410 exam, this topic tests your understanding of DHCPv6 operations and the specific options used for stateless and stateful address configuration. A common trap is confusing Option 23 with Option 24 (Domain Search List), which provides domain suffixes rather than server addresses. Remember the memory tip: "23 for DNS servers, 24 for search domains" — think of the number 23 as the two letters "D" and "N" in the alphabet (D=4, N=14, sum 18, but close enough to anchor the concept that Option 23 is the one that gives you the DNS server list).
This 300-410 practice question tests your understanding of dhcp (ipv4 and ipv6). 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 DHCPv6 option carries the DNS recursive name server information?
Option 6 (Domain Name Server)
Why wrong: Option 6 is for DHCPv4, not DHCPv6.
Option 23 (DNS Recursive Name Server)
Option 23 is the DHCPv6 option for DNS servers.
Option 24 (Domain Search List)
Why wrong: Option 24 is for domain search list, not DNS server addresses.
Option 21 (SIP Server Domain Name)
Why wrong: Option 21 is for SIP servers, not DNS.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
Option 23 (DNS Recursive Name Server)
Option 23 (DNS Recursive Name Server) in DHCPv6 provides the list of DNS servers to clients, per RFC 3646.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
Option 6 (Domain Name Server)
Why it's wrong here
Option 6 is for DHCPv4, not DHCPv6.
Option 23 (DNS Recursive Name Server)
Why this is correct
Option 23 is the DHCPv6 option for DNS servers.
Related concept
Read the scenario before looking for a memorised answer.
Option 24 (Domain Search List)
Why it's wrong here
Option 24 is for domain search list, not DNS server addresses.
Option 21 (SIP Server Domain Name)
Why it's wrong here
Option 21 is for SIP servers, not DNS.
Common exam traps
Many certification questions include familiar terms but test a specific constraint. Read the exact wording before choosing an answer that is generally true but wrong for this case.
Detailed technical explanation
This question should be treated as a scenario, not a definition check. Identify the problem, the constraint and the best action. Then compare each option against those facts.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
A practitioner preparing for the 300-410 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
Identify which 300-410 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
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FAQ
DHCP (IPv4 and IPv6) — This question tests DHCP (IPv4 and IPv6) — Read the scenario before looking for a memorised answer..
The correct answer is: Option 23 (DNS Recursive Name Server) — Option 23 (DNS Recursive Name Server) in DHCPv6 provides the list of DNS servers to clients, per RFC 3646.
Identify which 300-410 exam domain this question belongs to, then review the specific concept being tested. Practise related questions in that domain and focus on understanding why each wrong answer is tempting — not just why the correct answer is right.
Read the scenario before looking for a memorised answer.
About these practice questions
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Last reviewed: Jun 19, 2026
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.
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