This LFCS practice question tests your understanding of networking. The scenario asks you to isolate a root cause — eliminate options that address a different problem before choosing. 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.
A user reports that they cannot reach a remote server by hostname but can reach it by IP address. Which configuration file is most likely misconfigured?
Clue words in this question
Noticing these words before you look at the options changes how you read each choice.
Clue: "most likely"
Why it matters: Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
/etc/resolv.conf specifies DNS servers; if misconfigured, DNS queries fail, causing hostname resolution to fail.
B
/etc/sysconfig/network
Why wrong: This file is not used on most modern distributions; it is deprecated in favor of /etc/sysconfig/network-scripts on RHEL-based systems but not directly related to DNS resolution.
C
/etc/hosts
Why wrong: /etc/hosts provides static hostname-to-IP mappings; if it were the sole issue, the hostname might resolve or not, but with DNS failure, this file is not the primary cause.
D
/etc/nsswitch.conf
Why wrong: /etc/nsswitch.conf controls the order of name resolution sources but does not configure DNS servers directly.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
/etc/resolv.conf
The /etc/resolv.conf file configures the system's DNS resolver, specifying the nameservers to query for hostname-to-IP resolution. If a user can reach a server by IP but not by hostname, it indicates that DNS resolution is failing, which is most commonly due to a missing or incorrect nameserver entry in /etc/resolv.conf.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
/etc/resolv.conf
Why this is correct
/etc/resolv.conf specifies DNS servers; if misconfigured, DNS queries fail, causing hostname resolution to fail.
Clue confirmation
The clue word "most likely" in the question point toward this answer.
Related concept
Read the scenario before looking for a memorised answer.
✗
/etc/sysconfig/network
Why it's wrong here
This file is not used on most modern distributions; it is deprecated in favor of /etc/sysconfig/network-scripts on RHEL-based systems but not directly related to DNS resolution.
✗
/etc/hosts
Why it's wrong here
/etc/hosts provides static hostname-to-IP mappings; if it were the sole issue, the hostname might resolve or not, but with DNS failure, this file is not the primary cause.
✗
/etc/nsswitch.conf
Why it's wrong here
/etc/nsswitch.conf controls the order of name resolution sources but does not configure DNS servers directly.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse /etc/resolv.conf with /etc/hosts or /etc/nsswitch.conf, thinking that a hostname resolution failure must be due to a missing static entry or a misconfigured lookup order, rather than the fundamental DNS resolver configuration.
Detailed technical explanation
How to think about this question
The resolver library (glibc) reads /etc/resolv.conf to determine which nameservers to query (e.g., 'nameserver 8.8.8.8') and search domains. If the file is missing, empty, or contains an unreachable nameserver, DNS queries will fail, causing hostname resolution to fail while IP-based connectivity remains intact. A common real-world scenario is when a DHCP client overwrites /etc/resolv.conf with incorrect or no nameservers, or when a static configuration is accidentally removed.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
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
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A practitioner preparing for the LFCS 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
Got this wrong? Here's your next step.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Networking — This question tests Networking — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: /etc/resolv.conf — The /etc/resolv.conf file configures the system's DNS resolver, specifying the nameservers to query for hostname-to-IP resolution. If a user can reach a server by IP but not by hostname, it indicates that DNS resolution is failing, which is most commonly due to a missing or incorrect nameserver entry in /etc/resolv.conf.
What should I do if I get this LFCS question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Are there clue words in this question I should notice?
Yes — watch for: "most likely". Probability qualifier — the question wants the most probable cause or outcome, not a guaranteed one. Eliminate low-probability options.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
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Question Discussion
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