Free Juniper JN0-253 Practice Exam with Questions & Answers | Set: 2

Bad cables are identified under the Layer 1 category within Marvis Actions. Juniper Mist’s documentation states: "Use the Actions dashboard to resolve Layer 1 issues. When you click the Layer 1 button on the Action dashboard, all available Layer 1 actions appear. This category currently contains only one action: bad cable." Marvis can detect and alert for bad cables based on frame errors, link statistics, and AP/Switch behavior, all under the Layer 1 category. Connectivity, security, and client issues are handled under their respective action categories, but bad cabling is specifically monitored and detected as a physical (Layer 1) fault.

TheJuniper Mist Cloud platformis built on amicroservices-based architecture, where individual software components perform specific functions and communicate using well-definedApplication Programming Interfaces (APIs).

According to theJuniper Mist Cloud Architecture and Operations Guide:

“Microservices communicate through secure APIs, allowing independent services to interact seamlessly while maintaining modularity and isolation.”

This architectural design provides major operational benefits, including:

Independent scalability– each service can scale based on workload demand.

Fault isolation– failures in one service do not affect others.

Continuous deployment– updates can be made to one service without impacting the rest of the platform.

Incorrect options:

B:Juniper Mist microservices are independently updated, not deployed as one suite.

C:They are independent, not dependent on one another.

D:Each microservice maintains its own data model; they do not rely on a single shared database.

Thus, the correct answer isA. Microservices communicate with each other using APIs.

Juniper Mist WAN Assuranceis a cloud-based service that extends Mist AI capabilities to the WAN edge, providing visibility, automation, and AI-driven analytics for WAN devices. It focuses on ensuringend-to-end service assurancefor users and applications across distributed networks.

According to theJuniper Mist WAN Assurance and SD-WAN Deployment Guide, the supported devices include:

“Juniper SRX Series Firewalls and Session Smart Routers (SSR) are integrated with Mist WAN Assurance for telemetry collection, service-level monitoring, and AI-driven troubleshooting.”

SRX Series Firewalls (A):Provide secure WAN connectivity and send real-time telemetry (including throughput, latency, and packet loss metrics) to Mist Cloud.

Session Smart Routers (C):Power the AI-driven SD-WAN solution with application-aware routing and session intelligence, fully integrated into Mist Cloud for advanced visibility and analytics.

EXandQFXswitches are used withWired Assurance, not WAN Assurance.

Therefore, the correct answers areA. SRX Series FirewallsandC. Session Smart Routers.

Radio Resource Management (RRM)is a key feature ofJuniper Mist Wireless Assurancethat uses AI-driven automation to dynamically adjust radio settings across access points (APs) for optimal wireless performance. The RRM engine ensures proper channel assignment, transmit power control, and interference management across the network.

According to theJuniper Mist Wireless Assurance and AI-Driven RRM Guide, RRM operates intwo modes:

Event-Driven RRM:This mode reacts immediately to real-time changes in the RF environment, such as new access points, interference spikes, or client density changes.

Global Optimization RRM:This process runs as ascheduled, system-wide optimization once per dayto evaluate the overall RF environment and redistribute channels and power settings network-wide for the best balance of coverage and capacity.

The documentation states:

“The RRM global optimization algorithm automatically executes once daily to ensure optimal channel and power planning across all APs.”

Thus, the correct answer isD – The RRM global optimization system automatically runs once a day.

From Juniper’s official guide:

“You’ll need either a claim code or an activation code to claim an AP. With either, you can claim an AP by using one of the following methods:

Mist AI Mobile App

A Web browser

You can claim either a single AP using a claim code or multiple APs using an activation code. You can use any of these methods to claim an AP:

To claim a single AP, use the claim/QR code located on the rear of the AP.

To claim multiple APs, you’ll need to use an activation code. When you purchase multiple APs, we provide you with an activation code along with your PO information.”​

From the Mist documentation:

“APs can be claimed to any organization by using either the activation code, claim code or QR code.

Activation Code: Whenever you order APs, our Sales Operations team will send you an activation code which can be used for claiming the APs and subscriptions as per the order. …

AP Claim Code: You can individually claim APs to your organization by navigating to Organization > Inventory > Claim APs and entering in the claim code found on the back of each AP.

AP QR Code: Using our Mist AI mobile app you can scan the QR code printed on the back of our APs to claim APs to your organization.”​

Summary:

The Juniper Mist platform allows you to claim an Access Point using:

Activation code (provided for bulk purchases, via PO)

Claim code (unique per AP, on the rear label)

QR code (scanned with the Mist AI mobile app, also encoded as the claim code)

These extracts are direct from Juniper’s own documentation and confirm the methods for AP onboarding in the Mist platform.

In theJuniper Mist Wireless Assurance dashboard, eachService Level Expectation (SLE)is broken down intosub-classifiersto identify the specific causes of degraded user experience. For theCapacity SLE, Mist AI analyzes performance indicators related to access point utilization, airtime availability, client density, and radio congestion.

According to theJuniper Mist Wireless Assurance Analytics Guide, sub-classifiers within the Capacity SLE may include:

WiFi Interference– measures co-channel and adjacent-channel interference.

Capacity– monitors total bandwidth and airtime utilization.

Network Issues– highlights backend transport or switching congestion.

Excessive Client Load– indicates when too many clients are associated with a single access point or radio, leading to reduced throughput and contention.

In the exhibit, theExcessive Client Loadbar clearly shows the highest contribution to the Capacity SLE degradation. This means that the majority of capacity issues were caused byan overloaded access point or radio channelhandling more clients than optimal.

Therefore, the correct answer isD. Excessive Client Load.

In theJuniper Mist Cloud, theClient Eventssection within theMonitoringinterface displays detailed event logs for both wired and wireless clients, providing insights into connectivity, authentication, and performance-related activities. Each event entry may include associated diagnostic files such asdynamic packet captures (DPCs),traceroute data, andsyslogsdepending on the event type and device context.

According to theJuniper Mist AI Operations and Client Event Diagnostics Guide, the platform states:

“Wireless client events provide correlation between client connection attempts and associated diagnostic artifacts such as dynamic packet captures. These files are generated automatically during troubleshooting events and are attached to the event log for administrator review.”

From the exhibit, theclient is shown as a wireless device, indicated by theWi-Fi iconand theSSID association informationvisible in the event details. Additionally, the entry confirms that adynamic packet capture (DPC)file was automatically generated for the event, allowing engineers to download and inspect packet-level activity for root-cause analysis.

Therefore:

B (It is a wireless client)is correct — the event pertains to a Wi-Fi-connected device.

C (A dynamic packet capture file is included)is correct — the log includes a downloadable DPC file.

Marvis Miniscontinuously validates the health of network services by performing synthetic tests at predefined intervals without requiring user intervention. These tests simulate real client interactions — such as authentication, DHCP, DNS, and application reachability — to detect network issues proactively.

According to theJuniper Mist Marvis Minis Technical Overview, the feature performs:

“Automated validations every hour to ensure wireless, wired, and WAN network services are operating as expected.”

Each validation cycle allows the Minis agent (running on Mist Access Points) to verify connectivity and performance parameters across key stages of the client experience. If any issues are detected, they are automatically surfaced in theMarvis Actions dashboardfor further analysis.

While administrators can trigger additional manual tests,automatic validations occur every hourby default across all enabled sites.

Therefore, the correct answer isB. Every hour.

InJuniper Mist AI,Service Level Expectations (SLEs)form the foundation ofWireless AssuranceandWired Assurance. They provide adata-driven, proactive methodto measure and maintain the quality of user experience, going beyond traditional device-centric monitoring.

According to theJuniper Mist AI Operations GuideandWireless Assurance Documentation, SLEs:

“Leverage machine learning and data science to deliver a proactive understanding of end-user experience and identify root causes of performance issues.”

Each SLE (such asTime to Connect,Roaming,Throughput,Coverage, andCapacity) is composed ofclassifiers, which break down performance metrics into measurable, root-cause categories. Examples includeDHCP,DNS,Authentication, andSignal Qualityclassifiers.

This classifier-based structure enables Mist AI to automatically correlate problems and highlight the most probable cause of degradation—eliminating the need for manual troubleshooting or reactive analysis.

OptionsBandDare incorrect because SLEs arenot ad hoc toolsfor manual troubleshooting and donot simply list connected clients. Instead, they provide intelligent, AI-driven insights into user experience across the network.

Therefore, the correct statements are:

A. SLEs use machine learning to provide a proactive approach to understanding the end-user experience.

C. The metrics analyzed to meet specific SLE goals are categorized into classifiers.

In theJuniper Mist Cloud,webhooksare used to sendreal-time event notificationsfrom Mist Cloud to external systems such as third-party monitoring or automation platforms. This integration mechanism allows administrators to collect alerts, status changes, and analytics data directly from Mist Cloud without the need for constant API polling.

According to theJuniper Mist API and Webhook Integration Guide, webhooks are defined as:

“A push-based communication method that enables Juniper Mist Cloud to send event data to a customer-defined HTTP endpoint when specific network events occur.”

This capability allows seamless integration with enterprise monitoring solutions such asServiceNow,Splunk, orDatadog, enabling organizations to centralize event management.

The other options are not suitable:

A (API):APIs are pull-based and require polling for updates, not push notifications.

B (Email):Not supported for automated system-to-system event delivery.

D (WebSocket):Used for live telemetry and streaming data (e.g., client updates), not event alerts.

Therefore, the correct method isC. Using a webhook.