This LFCS practice question tests your understanding of networking. This is a configuration task: choose the command set that satisfies every stated requirement. Small differences — like 'secret' vs 'password' or 'transport input ssh' vs 'all' — change whether the answer is correct. 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.
Which TWO configuration files are commonly used to set DNS resolver settings on a Linux system?
/etc/nsswitch.conf
Controls order of name resolution (e.g., files, dns).
/etc/hostname
Why wrong: Sets the hostname only.
/etc/sysconfig/network
Why wrong: Contains general network settings, not DNS resolver.
/etc/hosts
Why wrong: Contains static hostname mappings.
/etc/resolv.conf
Contains nameserver and search domain settings.
Answer choices
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
/etc/nsswitch.conf
Option A is correct because /etc/nsswitch.conf controls the order of name resolution sources (e.g., files, dns, mdns) via the 'hosts' database line. Option E is correct because /etc/resolv.conf directly specifies the DNS resolver settings, including nameserver IP addresses, search domains, and options, as defined by RFC 1035.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
For each option: why learners choose it and why it is or isn't the right answer here.
/etc/nsswitch.conf
Why this is correct
Controls order of name resolution (e.g., files, dns).
Related concept
Read the scenario before looking for a memorised answer.
/etc/hostname
Why it's wrong here
Sets the hostname only.
/etc/sysconfig/network
Why it's wrong here
Contains general network settings, not DNS resolver.
/etc/hosts
Why it's wrong here
Contains static hostname mappings.
/etc/resolv.conf
Why this is correct
Contains nameserver and search domain settings.
Related concept
Read the scenario before looking for a memorised answer.
Common exam traps
The trap here is that candidates often confuse /etc/hosts with a DNS resolver configuration file, but it is only a static local lookup table, not a resolver setting file.
Detailed technical explanation
The resolver library (glibc) reads /etc/resolv.conf to determine which DNS servers to query and in what order; the 'nameserver' directive can appear up to three times. The 'hosts' line in /etc/nsswitch.conf (e.g., 'hosts: files dns') dictates that the system first checks /etc/hosts before querying DNS, which can be critical for troubleshooting resolution order or bypassing DNS for local entries.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
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
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
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FAQ
Networking — This question tests Networking — Read the scenario before looking for a memorised answer..
The correct answer is: /etc/nsswitch.conf — Option A is correct because /etc/nsswitch.conf controls the order of name resolution sources (e.g., files, dns, mdns) via the 'hosts' database line. Option E is correct because /etc/resolv.conf directly specifies the DNS resolver settings, including nameserver IP addresses, search domains, and options, as defined by RFC 1035.
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
Read the scenario before looking for a memorised answer.
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Last reviewed: Jun 25, 2026
This LFCS practice question is part of Courseiva's free Linux Foundation 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 LFCS exam.
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