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JNCIA-Junos Cheat Sheet 2026: One-Page Review of Must-Know Facts

TL;DR
  • JN0-106 has 65 questions, runs 90 minutes, and costs $200 through Pearson VUE or OnVUE.
  • JN0-106 replaced JN0-105 on April 6, 2026 and is based on Junos OS 21.2.
  • Seven domains structure the exam, from Networking Fundamentals through Routing Policy and Firewall Filters.
  • No prerequisite certification is required, and results appear as pass/fail immediately after testing.

Exam Snapshot: The Numbers You Must Know

Before diving into command syntax, lock in the mechanics of the exam itself. These are the facts that determine how you register, how you pace your study, and how you schedule test day. If you want the full breakdown behind these numbers, the JNCIA-Junos Certification Cost breakdown and JNCIA-Junos Exam Dates guide go deeper than this quick-reference sheet.

DetailFact
Exam codeJN0-106
Administered byPearson VUE (test center or OnVUE online proctoring)
Cost$200 USD
Questions65, multiple-choice
Time limit90 minutes
LanguageEnglish
ResultsPass/fail reported immediately
PrerequisiteNone
Software basisJunos OS 21.2
Validity3 years
ReplacedJN0-105, retired April 6, 2026
Registration Reminder: Since JN0-106 replaced JN0-105 on April 6, 2026, make sure any study material or practice questions you use reference Junos OS 21.2. Older material tied to JN0-105 may include outdated CLI behavior or removed features.

The 7 Domains at a Glance

Every JN0-106 question maps to one of seven domains. Memorizing these names and their weight in your own study plan is more useful than any generic "know the OSI model" advice. For a full walkthrough of what each domain tests, see the JNCIA-Junos Exam Domains complete guide.

Domain 1: Networking Fundamentals

Covers OSI layers, encapsulation, IPv4/IPv6 addressing, and basic switching/routing concepts that underpin everything else on the exam.

  • Subnetting math and address classes
  • Layer 2 vs. Layer 3 forwarding behavior

Domain 2: Junos OS Fundamentals

Tests your understanding of the Junos architecture, including separation of the control plane and forwarding plane, and the software's modular process design.

  • Routing Engine vs. Packet Forwarding Engine roles
  • Junos daemons (rpd, chassisd, mgd)

Domain 3: User Interfaces

Focuses on the CLI and J-Web, including navigation, keyboard shortcuts, and command completion.

  • Operational vs. configuration mode prompts
  • Using ? and Tab for command help/completion

Domain 4: Configuration Basics

Covers the candidate configuration workflow: editing, committing, rolling back, and validating changes.

  • commit confirmed and rollback numbering
  • Hierarchical configuration structure

Domain 5: Operational Monitoring and Maintenance

Tests your ability to check device health, interpret logs, and perform basic file and software maintenance.

  • show commands for interfaces, routes, and system health
  • Log file locations and basic troubleshooting sequence

Domain 6: Routing Fundamentals

Covers static routing, dynamic routing protocol basics, and how the routing table interacts with the forwarding table.

  • Routing table vs. forwarding table distinction
  • Static route configuration syntax

Domain 7: Routing Policy and Firewall Filters

Tests policy application points, filter logic, and how match/action terms are structured.

  • Import vs. export policy application
  • Firewall filter term order and default behavior

Key Takeaway

Treat each of these seven domain names as a study module. If a topic doesn't clearly fit under one of them, it's probably not exam-relevant for JN0-106.

Question Format and Testing Mechanics

JN0-106 is entirely multiple-choice - there are no drag-and-drop, simulation, or fill-in-the-blank items. Questions typically present a short scenario or CLI output snippet and ask you to identify the correct command, the expected behavior, or the misconfigured element.

  • 65 questions in 90 minutes works out to roughly 80 seconds per question on average - enough time to read carefully but not enough to second-guess every answer.
  • No penalty for wrong answers is standard in Pearson VUE-administered Juniper exams, so answer every question rather than leaving blanks.
  • Pass/fail feedback is immediate, meaning you'll know your result before you leave the testing session.

If you're trying to gauge how challenging this format actually is compared to other associate-level certs, the JNCIA-Junos difficulty guide and JNCIA-Junos Pass Rate analysis both dig into what the exam experience is really like. For a precise breakdown of what "passing" actually requires on this scoring model, check the JNCIA-Junos Passing Score guide.

Junos Command Syntax Cheat Sheet

These are the command patterns candidates most often misremember on exam day. Keep this list handy during final review.

TaskCommand Pattern
Enter configuration modeconfigure
View pending changesshow | compare
Commit with auto-rollback safety netcommit confirmed
Roll back to previous configrollback 1
Check interface statusshow interfaces terse
View active routesshow route
Display system alarmsshow system alarms
Save config to a filesave filename
Common Trap: Candidates frequently confuse commit with commit confirmed. The latter automatically reverts the configuration if a second commit isn't issued within the specified window - a favorite scenario for Domain 4 questions.

CLI Modes and Configuration Concepts

Junos separates operational mode (monitoring, "show" commands) from configuration mode (editing the candidate configuration). Understanding how these two modes interact is foundational to both Domain 3 and Domain 4.

  • Operational mode prompt ends with >; used for monitoring and diagnostics.
  • Configuration mode prompt ends with #; used for editing the candidate configuration hierarchy.
  • Candidate vs. active configuration: changes only take effect after a commit.
  • Hierarchy navigation: use edit to move into a stanza, up or top to move back out.

These concepts appear constantly in scenario-based questions, where you're shown a CLI snippet and asked what mode the device is in or what the next logical command would be. If you're building a structured plan around these mechanics rather than just memorizing commands in isolation, the JNCIA-Junos Study Guide walks through a full first-attempt strategy.

Routing Policy and Firewall Filter Shortcuts

Domain 7 trips up a lot of candidates because policy and filter logic look similar but behave differently. Keep these distinctions straight:

  • Routing policies influence which routes get imported into or exported from the routing table; applied with import or export statements under a protocol or routing-options.
  • Firewall filters control packet forwarding decisions (accept, discard, reject) and are applied directly to interfaces.
  • Term order matters in both - the first matching term wins, and there's an implicit "deny/discard" if nothing matches in most filter configurations.
  • Match conditions can be based on protocol, prefix, port, or interface, depending on whether you're writing a policy or a filter.

Key Takeaway

When a question describes traffic being unexpectedly dropped, check whether the scenario involves a firewall filter's implicit deny or a routing policy that never explicitly permits the route.

The Week-Before Review Plan

A cheat sheet works best paired with a short, focused review cycle rather than cramming everything the night before. Spend the final week rotating through domains rather than re-reading notes linearly - active recall on Junos-specific commands beats passive review.

Days 7-6

Networking Fundamentals + Junos OS Fundamentals

  • Redo subnetting drills and Routing Engine/PFE separation questions
  • Practice explaining Junos architecture out loud, in one sentence
Days 5-4

User Interfaces + Configuration Basics

  • Rehearse commit, rollback, and compare commands from memory
  • Time yourself navigating the configuration hierarchy
Days 3-2

Operational Monitoring + Routing Fundamentals

  • Review common show command outputs
  • Practice reading routing tables and identifying the best route
Day 1

Routing Policy and Firewall Filters + Full Review

If you want a deeper explanation of study methodology beyond this compressed timeline - including how to sequence weeks earlier in your prep, not just the final stretch - the JNCIA-Junos Study Guide covers that in more detail.

Who This Certification Actually Helps

JN0-106 has no prerequisite certification, which makes it accessible to network administrators, help desk technicians moving into infrastructure roles, and students targeting service provider or enterprise networking jobs. Organizations running Juniper hardware - particularly service providers, data center operators, and enterprises with Juniper switching or routing gear - often look for this credential as a baseline signal of Junos familiarity.

Because the certification only lasts three years, factor recertification into your career planning; renewing through an approved Juniper course (such as Introduction to the Junos Operating System or a higher-level course in the same track) keeps your credential active without retaking the full exam from scratch. For a broader look at where this credential fits in a networking career path and what it's actually worth pursuing, see Is the JNCIA-Junos Certification Worth It? and the JNCIA-Junos Salary Guide. If you're still deciding whether you even qualify to sit for it, the JNCIA-Junos Requirements guide confirms there's no formal prerequisite. And if you're browsing roles that list this credential, the JNCIA-Junos Jobs overview and JNCIA-Junos Training guide are useful next stops.

Quick Terminology Check: New to the acronym itself? The What Is JNCIA-Junos? and JNCIA-Junos Meaning pages explain what JNCIA-Junos stands for and clarify what the credential actually certifies before you go further into exam prep.

Whichever stage of prep you're at, revisit this page as a fast refresher rather than a full study resource - pair it with timed practice questions on the JNCIA-Junos practice exam hub to see how these facts translate into actual scored performance.

Frequently Asked Questions

Is JN0-106 the current JNCIA-Junos exam code for 2026?

Yes. JN0-106 replaced JN0-105 on April 6, 2026, and is based on Junos OS 21.2. Make sure any study materials you use reflect this version.

Do I need a prerequisite certification to sit for JN0-106?

No. There is no prerequisite certification required for JNCIA-Junos. Anyone can register and schedule the exam through Pearson VUE.

How many questions are on the exam and how much time do I get?

The exam contains 65 multiple-choice questions and has a 90-minute time limit, delivered in English through Pearson VUE test centers or OnVUE online proctoring.

How long does the JNCIA-Junos certification stay valid?

It's valid for three years. You can recertify by completing an approved Juniper course, such as Introduction to the Junos Operating System or a higher-level course in the same track.

When will I know if I passed?

Pass/fail status is reported immediately after you finish the exam, whether you test at a physical Pearson VUE center or through OnVUE online proctoring.

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