- A
DNS: Users cannot access the website by name but can by IP
High CPU utilization directly causes slowness because the device lacks processing capacity to handle traffic efficiently, leading to delays in forwarding decisions.
- B
DHCP: Clients receive IP addresses from a different subnet
CRC errors indicate physical layer issues like faulty cables or interference, not congestion. Congestion is indicated by packet drops or queue fills.
- C
Web server: HTTP 500 errors on the application
Packet drops are a symptom of congestion or buffer overflow, not directly high latency. High latency is caused by propagation delay, serialization delay, or queuing delay.
- D
Database: Slow query responses and timeouts
Flapping interfaces are caused by hardware issues or unstable links, not routing loops. Routing loops result from misconfigured routing protocols or incorrect route redistribution.
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 resolves human-readable domain names into IP addresses, and failure in DNS causes name-resolution errors in network troubleshooting.. 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.
Match each service to the symptom it most directly relates to when troubleshooting.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
DNS: Users cannot access the website by name but can by IP
Each service is paired with a symptom directly related to its malfunction.
Key principle: DNS resolves human-readable domain names into IP addresses, and failure in DNS causes name-resolution errors in network troubleshooting.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
DNS: Users cannot access the website by name but can by IP
Why this is correct
High CPU utilization directly causes slowness because the device lacks processing capacity to handle traffic efficiently, leading to delays in forwarding decisions.
Related concept
DNS resolves human-readable domain names into IP addresses, and failure in DNS causes name-resolution errors in network troubleshooting.
- ✓
DHCP: Clients receive IP addresses from a different subnet
Why this is correct
CRC errors indicate physical layer issues like faulty cables or interference, not congestion. Congestion is indicated by packet drops or queue fills.
Related concept
DNS resolves human-readable domain names into IP addresses, and failure in DNS causes name-resolution errors in network troubleshooting.
- ✓
Web server: HTTP 500 errors on the application
Why this is correct
Packet drops are a symptom of congestion or buffer overflow, not directly high latency. High latency is caused by propagation delay, serialization delay, or queuing delay.
Related concept
DNS resolves human-readable domain names into IP addresses, and failure in DNS causes name-resolution errors in network troubleshooting.
- ✓
Database: Slow query responses and timeouts
Why this is correct
Flapping interfaces are caused by hardware issues or unstable links, not routing loops. Routing loops result from misconfigured routing protocols or incorrect route redistribution.
Related concept
DNS resolves human-readable domain names into IP addresses, and failure in DNS causes name-resolution errors in network troubleshooting.
Common exam traps
Common exam trap: answer the scenario, not the keyword
Be careful not to confuse symptoms that often occur together (like congestion causing both drops and latency) with direct cause-and-effect relationships. The question asks for the most direct symptom, not a correlated one.
Detailed technical explanation
How to think about this question
DNS (Domain Name System) is a fundamental IP service that translates human-friendly domain names into IP addresses that routers and hosts use to communicate. When DNS fails, users cannot resolve domain names, resulting in name-resolution failures that prevent access to websites or network resources by name. Cisco devices often use DNS for management and routing protocols, so DNS issues can affect multiple network functions. DHCP (Dynamic Host Configuration Protocol) automates the assignment of IP addresses, subnet masks, default gateways, and other network parameters to hosts. If DHCP fails, hosts do not receive proper network configuration, leading to missing or incorrect IP settings. This causes connectivity issues and prevents devices from joining the network correctly. Cisco routers and switches can act as DHCP servers or relay agents, so understanding DHCP behavior is vital for troubleshooting. NTP (Network Time Protocol) ensures all network devices synchronize their clocks to a common time source. Accurate timestamps are critical for logging, security protocols, and time-sensitive applications. When NTP is misconfigured or unavailable, devices experience timestamp misalignment, which complicates event correlation and troubleshooting. NetFlow is a traffic monitoring protocol that collects IP flow data to analyze bandwidth usage and traffic patterns. Without NetFlow, network administrators lose visibility into traffic conversations, making it difficult to identify bottlenecks or malicious activity. Recognizing these symptoms and associating them with the correct IP service is essential for effective network troubleshooting in Cisco environments.
KKey Concepts to Remember
- DNS resolves human-readable domain names into IP addresses, and failure in DNS causes name-resolution errors in network troubleshooting.
- DHCP dynamically assigns IP addresses and network configuration to hosts, so DHCP failure results in missing or incorrect automatic host configuration.
- NTP synchronizes device clocks across the network, and NTP failure leads to timestamp misalignment affecting logs and time-sensitive protocols.
- NetFlow collects and exports IP traffic flow data, providing visibility into traffic conversations and bandwidth usage for network monitoring and troubleshooting.
- When troubleshooting IP services, matching symptoms to the correct service helps isolate the root cause quickly and efficiently.
- Understanding the specific function of each IP service is critical to correctly diagnosing network issues in Cisco CCNA environments.
- Cisco devices rely on these IP services to maintain network stability, security, and performance, making their correct operation essential.
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 resolves human-readable domain names into IP addresses, and failure in DNS causes name-resolution errors in network troubleshooting.
Real-world example
How this comes up in practice
A network engineer segments a warehouse floor into three subnets: 20 scanners, 5 printers, and 2 management hosts. Picking the wrong mask wastes addresses or leaves too few usable hosts. Exam questions test whether you can apply CIDR notation, calculate block size, and identify the correct usable-host range for a given prefix.
What to study next
Got this wrong? Here's your next step.
Review dNS resolves human-readable domain names into IP addresses, and failure in DNS causes name-resolution errors in network troubleshooting., then practise related 200-301 questions on the same topic to reinforce the concept.
- →
Network Services and Security — study guide chapter
Learn the concepts, then practise the questions
- →
Network Services and Security practice questions
Targeted practice on this topic area only
- →
All 200-301 questions
1,819 questions across all exam domains
- →
CCNA 200-301 v2 study guide
Full concept coverage aligned to exam objectives
- →
200-301 practice test guide
How to use practice tests most effectively before exam day
Related practice questions
Related 200-301 practice-question pages
Use these pages to review the topic behind this question. This is how one missed question becomes focused revision.
Network Infrastructure and Connectivity practice questions
Practise 200-301 questions linked to Network Infrastructure and Connectivity.
Switching and Network Access practice questions
Practise 200-301 questions linked to Switching and Network Access.
IP Routing practice questions
Practise 200-301 questions linked to IP Routing.
Network Services and Security practice questions
Practise 200-301 questions linked to Network Services and Security.
AI and Network Operations practice questions
Practise 200-301 questions linked to AI and Network Operations.
CCNA subnetting practice questions
Practise IPv4 subnetting, CIDR, masks, host ranges and subnet selection.
CCNA OSPF practice questions
Practise OSPF neighbours, router IDs, metrics, areas and routing-table interpretation.
CCNA VLAN practice questions
Practise VLANs, access ports, trunks, allowed VLANs and switching scenarios.
CCNA STP practice questions
Practise spanning tree, root bridge election, port roles and STP troubleshooting.
CCNA EtherChannel practice questions
Practise LACP, PAgP, port-channel behaviour and bundle requirements.
CCNA ACL practice questions
Practise standard and extended ACLs, permit/deny logic and traffic filtering.
CCNA NAT practice questions
Practise static NAT, dynamic NAT, PAT and inside/outside address translation.
Practice this exam
Start a free 200-301 practice session
Short sessions build daily habit. Longer sessions build exam-day stamina. Try a timed session to simulate real conditions.
FAQ
Questions learners often ask
What does this 200-301 question test?
Network Services and Security — This question tests Network Services and Security — DNS resolves human-readable domain names into IP addresses, and failure in DNS causes name-resolution errors in network troubleshooting..
What is the correct answer to this question?
The correct answer is: DNS: Users cannot access the website by name but can by IP — Each service is paired with a symptom directly related to its malfunction.
What should I do if I get this 200-301 question wrong?
Review dNS resolves human-readable domain names into IP addresses, and failure in DNS causes name-resolution errors in network troubleshooting., then practise related 200-301 questions on the same topic to reinforce the concept.
What is the key concept behind this question?
DNS resolves human-readable domain names into IP addresses, and failure in DNS causes name-resolution errors in network troubleshooting.
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 →
Last reviewed: May 17, 2026
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.