Question 1hardmultiple choice
Full question →hardmultiple choiceObjective-mapped
Exhibit
PC output: C:\> ping 8.8.8.8 -> success C:\> ping www.example.com -> Ping request could not find host www.example.com
Exhibit: A client can ping 8.8.8.8 but cannot browse to www.example.com. Which service is most likely failing?
Answer choices
Why each option matters
Good practice is not just finding the correct option. The wrong answers often show the exact trap the exam wants you to fall into.
A
Distractor review
NTP
Distractor.
B
Best answer
DNS
Correct choice.
C
Distractor review
DHCP snooping
Distractor.
D
Distractor review
HSRP
Distractor.
Common exam trap
Common exam trap: answer the scenario, not the keyword
A frequent exam trap is assuming that successful ping to an IP address means all network services are functioning correctly. Candidates often overlook that ping uses numeric IP addresses and does not test DNS resolution. This leads to the incorrect conclusion that the network is fully operational, causing them to eliminate DNS as a problem. The trap is reinforced by the presence of other options like DHCP snooping or HSRP, which are unrelated to hostname resolution but may seem plausible. Recognizing that DNS specifically enables hostname-to-IP translation is essential to avoid this mistake.
Technical deep dive
How to think about this question
DNS (Domain Name System) is a critical IP service that translates human-friendly domain names into IP addresses required for routing traffic on the internet. When a client types www.example.com into a browser, the DNS client sends a query to a DNS server to resolve that name into an IP address. Without this translation, the client cannot initiate a connection to the web server hosting the site. DNS operates over UDP and TCP on port 53 and is fundamental for hostname-based communication in IP networks. In the scenario where a client can ping 8.8.8.8 but cannot browse www.example.com, the key diagnostic clue is that IP connectivity exists but hostname resolution fails. This indicates that the DNS service is either misconfigured, unreachable, or down. The client’s DNS settings might be incorrect, or the DNS server itself might be offline. Unlike DHCP snooping or HSRP, which affect network security or gateway redundancy respectively, DNS directly impacts the ability to resolve domain names, making it the most likely failing service. A common exam trap is confusing IP connectivity with full network functionality. Because ping uses IP addresses directly, it can succeed even if DNS is broken, misleading candidates to think the network is fully operational. In practical Cisco environments, DNS issues often cause user complaints about web access despite successful pings. Understanding this distinction helps avoid misdiagnosis and ensures correct troubleshooting steps focus on DNS rather than routing or other IP services.
KKey Concepts to Remember
- DNS resolves human-readable domain names into IP addresses, enabling clients to access websites using hostnames instead of numeric IPs.
- A client can ping an IP address directly without DNS, but browsing a website by name requires successful DNS resolution.
- If a client can ping an external IP like 8.8.8.8 but cannot browse a domain name, the DNS service is likely failing or unreachable.
- DHCP snooping is a security feature that prevents unauthorized DHCP servers but does not affect DNS resolution directly.
- NTP synchronizes device clocks and does not impact the ability to resolve domain names or browse websites.
- HSRP provides gateway redundancy and does not influence DNS or hostname resolution for client devices.
- DNS failures often manifest as inability to resolve hostnames, even when IP connectivity is verified by pinging IP addresses.
- Troubleshooting DNS issues involves verifying DNS server configuration, client DNS settings, and network reachability to DNS servers.
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.
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.
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.
CCNA DHCP practice questions
Practise DHCP scopes, relay, leases and troubleshooting.
CCNA show ip route practice questions
Practise routing-table output, longest-prefix match, AD and route selection.
CCNA show interfaces trunk practice questions
Practise trunk verification and VLAN forwarding across switches.
CCNA wireless security practice questions
Practise WLAN security, authentication and wireless architecture concepts.
CCNA IPv6 practice questions
Practise IPv6 addressing, routes, neighbour discovery and common IPv6 exam traps.
More questions from this exam
Keep practising from the same exam bank, or move into a focused topic page if this question exposed a weak area.
Question 1
A router learns the same prefix from both OSPF and EIGRP. Which route is installed by default?
Question 2
A router shows this output: R1#show ip ospf neighbor Neighbor ID Pri State Dead Time Address Interface 10.1.1.2 1 FULL/DR 00:00:34 192.168.12.2 GigabitEthernet0/0 10.1.1.3 1 2WAY/DROTHER 00:00:39 192.168.12.3 GigabitEthernet0/0 Which statement is correct?
Question 3
What is the OSPF metric called?
Question 4
A non-root switch has two uplinks toward the root bridge. One path has a lower total STP cost than the other. What role will the lower-cost uplink have?
Question 5
A router interface applies this ACL inbound: 10 deny tcp any any eq 80 20 permit ip any any A user reports that web browsing to a server by IP address fails, but ping works. Which statement best explains the behavior?
Question 6
A router learns route 198.51.100.0/24 from OSPF with AD 110 and also has a static route to the same prefix configured with AD 150. Which route is installed?
FAQ
Questions learners often ask
What does this 200-301 question test?
DNS resolves human-readable domain names into IP addresses, enabling clients to access websites using hostnames instead of numeric IPs.
What is the correct answer to this question?
The correct answer is: DNS — The client has IP connectivity because it can reach 8.8.8.8 directly. The problem appears only when using a hostname, which points to a DNS resolution issue rather than a routing issue.
What should I do if I get this 200-301 question wrong?
Then try more questions from the same exam bank and focus on understanding why the wrong options are tempting.
Discussion
Loading comments…
Sign in to join the discussion.