easyMultiple ChoiceObjective-mapped
220-1201 Practice Question: A user complains that their desktop computer…
A user complains that their desktop computer cannot connect to any network shares, but they can access the internet. The technician pings the file server by IP address successfully, but pinging by hostname fails. Which network configuration issue is most likely causing this problem?
⚠ Common exam trap
Watch out — candidates often assume a firewall is blocking ICMP (Option D) because they see a ping failure, but the successful ping by IP proves the firewall is not the issue, and the real problem is DNS resolution for local hostnames.
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
✓
The DNS server is not resolving local hostnames.
The user can access the internet (which relies on external DNS resolution) and can ping the file server by IP address, but cannot ping by hostname. This indicates that the local DNS server is failing to resolve the file server's hostname to its IP address. Since the user can reach the internet, the default gateway and subnet mask are likely correct, and the file server's firewall is not blocking ICMP because the IP-based ping succeeds.
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 DHCP server is not assigning a default gateway.
Why it's wrong here
A default gateway is essential for a host to communicate with devices outside its local subnet, including the internet. If the DHCP server failed to assign a default gateway, the desktop computer would be unable to route traffic to external networks, resulting in a complete loss of internet access. Since the user can successfully access the internet, the default gateway is clearly assigned and functioning correctly, making this option incorrect.
- ✗
The subnet mask is incorrect.
Why it's wrong here
An incorrect subnet mask would misdefine the network portion of an IP address, leading to a host incorrectly identifying which devices are on its local subnet versus those requiring a router. This misconfiguration would severely impair both local network communication and internet connectivity, as the host would struggle to determine proper routing for any destination. Given that IP-based pings to the file server succeed, indicating local network reachability, the subnet mask is likely configured correctly.
- ✓
The DNS server is not resolving local hostnames.
Why this is correct
When a technician can successfully ping a file server by its IP address but fails to ping it by its hostname, it strongly indicates a problem with name resolution. The Domain Name System (DNS) server is responsible for translating human-readable hostnames into numerical IP addresses. In this scenario, the DNS server is failing to provide the correct A record for the local file server's hostname, preventing the desktop from locating the server by name, even though its network path via IP is functional.
- ✗
The file server has a firewall blocking ICMP.
Why it's wrong here
The Internet Control Message Protocol (ICMP) is used by the ping utility to test network connectivity. If the file server's firewall were configured to block incoming ICMP echo requests, both pings by IP address and pings by hostname would fail, as the server would not respond to the diagnostic packets. Since the technician successfully pinged the file server using its IP address, the file server's firewall is clearly not blocking ICMP, making this option an incorrect diagnosis.
Visual reference
Quick reference
IPv4 Address Class Summary
| Class | First Octet Range | Default Mask | Networks | Hosts per Network |
|---|---|---|---|---|
| A | 1–126 | /8 (255.0.0.0) | 126 | 16,777,214 |
| B | 128–191 | /16 (255.255.0.0) | 16,384 | 65,534 |
| C | 192–223 | /24 (255.255.255.0) | 2,097,152 | 254 |
| D | 224–239 | N/A | Multicast groups | — |
| E | 240–255 | N/A | Reserved / experimental | — |
127.x.x.x is reserved for loopback. Modern networks use CIDR (classless) rather than classful addressing.
Go deeper
Related to this question
Learn chapter
Network Configuration: IP, DNS, DHCP
Key term
ICMP
ICMP is a network protocol used by devices to send error messages and operational information about network communication problems.
Key term
Subnet
A subnet is a logical subdivision of an IP network, created by partitioning a larger network address space using subnet masks.
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JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 220-1201 practice question is part of Courseiva's free CompTIA 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 220-1201 exam.