The correct statements are that the 'system' hierarchy includes settings for NTP and DNS, and the 'interfaces' hierarchy configures both physical and logical interfaces. This is because the Junos configuration hierarchy is strictly organized by function: the 'system' stanza governs global device-level parameters like hostname, time synchronization (NTP), and name resolution (DNS), while the 'interfaces' stanza is dedicated to defining all network connectivity, from physical ports like ge-0/0/0 to logical subinterfaces like ge-0/0/0.100, including IP addresses, MTU, and VLAN tagging. On the JNCIA-Junos exam, this tests your understanding of where to place common settings—a frequent trap is confusing system-level services (like DNS) with interface-level parameters (like IP addresses). A useful memory tip: think of 'system' as the device’s brain (time, name, domain) and 'interfaces' as its hands (physical connections and logical tags).
JNCIA-JUNOS Junos Configuration Basics Practice Question
This JNCIA-JUNOS practice question tests your understanding of junos configuration basics. 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 are correct statements about the Junos configuration hierarchy?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
The 'interfaces' hierarchy is used to configure physical and logical interfaces.
Option B is correct because the 'interfaces' hierarchy in Junos is specifically designed to configure both physical interfaces (e.g., ge-0/0/0) and logical interfaces (e.g., ge-0/0/0.100), including parameters like IP addresses, MTU, and VLAN tagging. This is a fundamental part of Junos configuration, as all network traffic flows through interfaces defined under this hierarchy.
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.
✗
The 'routing-options' hierarchy is used to configure interface IP addresses.
The 'protocols' hierarchy includes system-level settings like hostname.
Why it's wrong here
System settings are under 'system'.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates often confuse the purpose of 'routing-options' with interface configuration, or assume that firewall filters belong under 'policy-options' because both involve policy-like constructs, but Junos strictly separates firewall (packet filtering) from routing policy (route manipulation).
Detailed technical explanation
How to think about this question
Under the hood, the Junos configuration is a hierarchical data structure that maps directly to the operation of the Junos OS daemons; for example, the 'interfaces' stanza is parsed by the interface process (ifd) to create kernel-level interface structures. A real-world scenario where this matters is when troubleshooting a missing IP address: a candidate might mistakenly look under 'routing-options' instead of 'interfaces', leading to wasted time. Additionally, the 'system' hierarchy controls the management plane, including NTP (ntp) and DNS (name-server), which are essential for network time synchronization and hostname resolution.
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 help-desk technician troubleshoots why a newly connected PC cannot reach shared printers on the same floor. The cable is good, the switch port is active, but the PC is in VLAN 20 and the printers are in VLAN 10. The uplink trunk only allows VLAN 10. A trunk being up does not mean every VLAN crosses it.
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.
Junos Configuration Basics — This question tests Junos Configuration Basics — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: The 'interfaces' hierarchy is used to configure physical and logical interfaces. — Option B is correct because the 'interfaces' hierarchy in Junos is specifically designed to configure both physical interfaces (e.g., ge-0/0/0) and logical interfaces (e.g., ge-0/0/0.100), including parameters like IP addresses, MTU, and VLAN tagging. This is a fundamental part of Junos configuration, as all network traffic flows through interfaces defined under this hierarchy.
What should I do if I get this JNCIA-JUNOS question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
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Variation 1. Which TWO statements are true about the Junos configuration hierarchy?
easy
A.Configuration is organized into two main hierarchies: system and interfaces.
✓ B.The configuration is divided into a hierarchical tree.
✓ C.Each configuration statement is terminated by a semicolon.
D.Configuration must be entered in a specific order.
E.It is a flat structure with no grouping.
Why B: The Junos configuration is organized as a hierarchical tree structure, where configuration statements are grouped under various hierarchy levels (e.g., 'system', 'interfaces', 'protocols'). Each statement in this tree is terminated by a semicolon, which is a fundamental syntax rule inherited from the Junos OS CLI. This hierarchical model allows for modular, structured configuration management.
Last reviewed: Jun 11, 2026
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This JNCIA-JUNOS practice question is part of Courseiva's free Juniper Networks 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 JNCIA-JUNOS exam.
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