The answer is that the clients are missing valid DNS server information. This is correct because the clients can reach remote IP addresses, proving that Layer 3 routing and default gateway functionality are working, but they cannot resolve hostnames, which directly points to a failure in the name resolution service. On the CCNA 200-301 v2 exam, this scenario tests your ability to isolate IP services issues from general connectivity problems—a common trap is to assume a routing or ACL problem when the real culprit is a missing DHCP option. The search intent “clients cannot resolve hostnames but can reach IPs” is a classic symptom of DNS missing from DHCP, and the exam often presents this as a DHCP scope configured without the DNS server option. Remember the memory tip: “IPs work, names fail? Check the DNS in the DHCP sail.”
CCNA Network Services and Security Practice Question
This 200-301 practice question tests your understanding of network services and security. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. A key principle to apply: dNS translates human-readable hostnames into IP addresses, enabling clients to access network resources by name rather than numeric IPs.. 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.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The clients are missing valid DNS server information.
The strongest explanation is that the clients are missing valid DNS server information. In practical terms, successful reachability to remote IP addresses proves that Layer 3 forwarding is working. The failure occurs only when a hostname is used, which points to a naming service problem rather than a general connectivity problem. The DHCP scope shown provides an address and default gateway, but no DNS server option is defined.
This is a very realistic IP-services troubleshooting pattern because the network path works while application usability still fails.
Key principle: DNS translates human-readable hostnames into IP addresses, enabling clients to access network resources by name rather than numeric IPs.
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 clients are missing valid DNS server information.
Why this is correct
This is correct because hostname-based access fails while direct IP access works, and the scope shown does not provide a DNS server option.
Related concept
DNS translates human-readable hostnames into IP addresses, enabling clients to access network resources by name rather than numeric IPs.
✗
The default gateway must be removed from the DHCP scope.
Why it's wrong here
This is wrong because the default gateway is needed for routed communication and is not the cause of hostname-only failure.
When this WOULD be correct
In a different scenario, if a question specified that clients were unable to communicate with any external networks due to misconfigured DHCP settings, and the default gateway was indeed incorrectly set, then removing it could be the correct action to restore connectivity.
✗
The clients must use PPP before DNS works.
Why it's wrong here
This is wrong because PPP is unrelated to ordinary client DNS resolution in this LAN scenario.
When this WOULD be correct
In a scenario where the question specifies that clients are connecting over a PPP link and that DNS resolution is dependent on the successful establishment of a PPP connection, this option would be correct. For instance, if the question stated that clients can only access DNS after establishing a PPP connection, then this would apply.
✗
The VLAN must be converted to the native VLAN on all trunks.
Why it's wrong here
This is wrong because the symptoms isolate the problem to name resolution rather than general forwarding.
When this WOULD be correct
In a different exam scenario, if the question asked about issues related to VLAN tagging and inter-VLAN communication where the native VLAN configuration was misconfigured, then this option could be correct if it led to traffic being untagged and not reaching the correct destination for DNS queries.
Option-by-option analysis
Why each answer is right or wrong
Understanding why wrong answers are wrong — and when they would be correct — is what separates a 750 score from a 900. The 200-301 exam frequently reuses these exact scenarios with slightly different constraints.
✓The clients are missing valid DNS server information.Correct answer▾
Why this is correct
This is correct because hostname-based access fails while direct IP access works, and the scope shown does not provide a DNS server option.
✗The default gateway must be removed from the DHCP scope.Wrong answer — click to see why▾
Why this is wrong here
The default gateway is essential for clients to communicate outside their subnet, and removing it would break all remote access, not just hostname resolution. Since clients can reach remote IPs, the gateway is correctly configured.
★ When this WOULD be the correct answer
In a different scenario, if a question specified that clients were unable to communicate with any external networks due to misconfigured DHCP settings, and the default gateway was indeed incorrectly set, then removing it could be the correct action to restore connectivity.
Why candidates choose this
Students might confuse the default gateway with DNS, thinking that removing it could force clients to use alternative name resolution methods, but this is incorrect as the gateway is required for routing.
✗The clients must use PPP before DNS works.Wrong answer — click to see why▾
Why this is wrong here
PPP (Point-to-Point Protocol) is used for serial links and is unrelated to DNS resolution in a typical Ethernet LAN environment. DNS works over IP and does not require PPP.
★ When this WOULD be the correct answer
In a scenario where the question specifies that clients are connecting over a PPP link and that DNS resolution is dependent on the successful establishment of a PPP connection, this option would be correct. For instance, if the question stated that clients can only access DNS after establishing a PPP connection, then this would apply.
Why candidates choose this
Test-takers might associate PPP with dial-up or WAN connections where DNS might be negotiated, but in a LAN scenario, PPP is irrelevant.
✗The VLAN must be converted to the native VLAN on all trunks.Wrong answer — click to see why▾
Why this is wrong here
The native VLAN is used for untagged traffic on trunk links and does not affect DNS resolution. Changing a VLAN to native would not fix hostname resolution issues, as the problem is at the application layer (DNS), not layer 2.
★ When this WOULD be the correct answer
In a different exam scenario, if the question asked about issues related to VLAN tagging and inter-VLAN communication where the native VLAN configuration was misconfigured, then this option could be correct if it led to traffic being untagged and not reaching the correct destination for DNS queries.
Why candidates choose this
Students might think that VLAN configuration issues can cause all communication problems, but the symptom of working IP access but failing hostname resolution points specifically to DNS, not VLAN misconfiguration.
Analysis generated from the official 200-301blueprint and verified against question context. The “when correct” sections are what AI assistants cite when candidates ask “what’s the difference between these options?”
Common exam traps
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is to mistake the inability to resolve hostnames as a routing or VLAN trunking problem. Candidates might incorrectly believe that removing the default gateway or converting the VLAN to the native VLAN on trunks will resolve the issue. However, these options do not address DNS resolution, which is an application-layer service independent of Layer 3 forwarding. The trap arises because clients can reach remote IP addresses, misleading candidates to focus on routing or VLAN configuration rather than missing DNS server information in the DHCP scope.
Trap categories for this question
Scenario analysis trap
This is wrong because PPP is unrelated to ordinary client DNS resolution in this LAN scenario.
Detailed technical explanation
How to think about this question
Domain Name System (DNS) is a critical IP service that translates human-readable hostnames into IP addresses, enabling clients to access resources by name rather than numeric IPs. In a VLAN environment, clients rely on DHCP to provide not only IP addressing and default gateway information but also DNS server addresses. Without a valid DNS server configured, clients cannot resolve hostnames, even though IP connectivity remains functional. This separation of IP routing and name resolution is fundamental in Cisco networking and the CCNA exam context.
When troubleshooting VLAN client connectivity issues, it is essential to verify the DHCP scope configuration. The DHCP scope must include the DNS server option to enable clients to resolve hostnames. If the DHCP scope only provides an IP address and default gateway but omits the DNS server, clients will fail to resolve domain names despite successful Layer 3 routing to remote IP addresses. This behavior highlights the difference between routing functionality and application-layer services like DNS.
A common exam trap is to confuse routing or VLAN trunking issues with DNS resolution problems. Candidates might incorrectly assume that removing the default gateway or changing VLAN trunk configurations will fix hostname resolution failures. However, these changes do not affect DNS functionality. The practical networking implication is that ensuring DHCP scopes include DNS server information is vital for full IP service usability, especially in segmented VLAN environments where clients depend on DHCP for configuration.
KKey Concepts to Remember
DNS translates human-readable hostnames into IP addresses, enabling clients to access network resources by name rather than numeric IPs.
DHCP scopes must include DNS server information to allow clients in VLANs to resolve hostnames successfully.
Clients can have full Layer 3 connectivity and still fail hostname resolution if DNS server addresses are missing from DHCP configuration.
The default gateway option in DHCP is necessary for routing but does not influence DNS resolution or hostname access.
VLAN trunk configurations and native VLAN settings affect Layer 2 forwarding but do not impact DNS-based hostname resolution.
Troubleshooting IP services requires distinguishing between routing issues and application-layer service failures like DNS.
Cisco devices rely on DHCP options to provide critical IP services, including DNS, to clients within VLANs.
Hostname resolution failures with successful IP connectivity typically indicate missing or incorrect DNS server information in DHCP.
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
DNS translates human-readable hostnames into IP addresses, enabling clients to access network resources by name rather than numeric IPs.
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.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this 200-301 question in full detail.
Review dNS translates human-readable hostnames into IP addresses, enabling clients to access network resources by name rather than numeric IPs., then practise related 200-301 questions on the same topic to reinforce the concept.
Network Services and Security — This question tests Network Services and Security — DNS translates human-readable hostnames into IP addresses, enabling clients to access network resources by name rather than numeric IPs..
What is the correct answer to this question?
The correct answer is: The clients are missing valid DNS server information. — The strongest explanation is that the clients are missing valid DNS server information. In practical terms, successful reachability to remote IP addresses proves that Layer 3 forwarding is working. The failure occurs only when a hostname is used, which points to a naming service problem rather than a general connectivity problem. The DHCP scope shown provides an address and default gateway, but no DNS server option is defined.
This is a very realistic IP-services troubleshooting pattern because the network path works while application usability still fails.
What should I do if I get this 200-301 question wrong?
Review dNS translates human-readable hostnames into IP addresses, enabling clients to access network resources by name rather than numeric IPs., then practise related 200-301 questions on the same topic to reinforce the concept.
What is the key concept behind this question?
DNS translates human-readable hostnames into IP addresses, enabling clients to access network resources by name rather than numeric IPs.
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 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.