JN0-253 Practice Exam Questions and Answers

In theJuniper Mist Cloud architecture, configuration hierarchy and inheritance are key design principles for managingEX SeriesandQFX Seriesswitches underWired Assurance. Configuration settings can be applied at both theorganization leveland thesite level, with clearly defined precedence rules.

According to theJuniper Mist Wired Assurance Configuration Guide, theorganization leveldefines global configuration templates that apply across multiple sites, while thesite levelprovides customization options specific to a particular location or environment.

The documentation states:

“Site-level configuration overrides any global or organizational template configurations for switches within that site.”

and further clarifies:

“Administrators can create or modify switch templates at the site level to apply custom settings to specific deployments without affecting other sites under the same organization.”

Thus:

Statement Cis correct — site-level configurations are an additional method to apply templates for a specific site.

Statement Dis correct — site-level configurationstake precedenceover org-level templates.

Statement Ais incorrect because org-level templates donotoverride site-level configurations; the reverse is true.

Statement Bis incorrect because site-level configuration isnot requiredfor manual switch setup—it is an optional, more efficient method of template application.

InJuniper Mist Cloud, guest access is managed through theGuest Portalfeature, which allows administrators to configure secure and flexible authentication methods for temporary or visitor access. These options are designed to provide a balance between user convenience and network security.

According to theJuniper Mist Guest Access and Captive Portal Configuration Guide, the supported authentication options include:

“Authentication Code (Self-registration) and Sponsored Guest workflows, among others, which provide different levels of administrative control and ease of use.”

Authentication Code (A):Visitors receive a temporary authentication code (PIN) via email or SMS that they use to log in. This method is ideal for self-service access while maintaining accountability.

Sponsored Guest (C):In this mode, guests must be approved by a designated employee or sponsor before gaining access. This adds an extra layer of security by involving internal personnel validation.

MAC Authentication (B)andSAML (D)are not used for guest portals; they are designed for device-based authentication and enterprise-level identity federation, respectively.

Marvis Minisis a feature withinMarvis Virtual Network Assistant (VNA)that proactively tests and validates network performance by simulating user connections. Instead of waiting for user complaints, it performssynthetic client transactionsto confirm the functionality of critical network services.

According to theJuniper Mist Marvis Minis Technical OverviewandMarvis AI Operations Guide, Minis validates several network functions automatically, including:

Dynamic Host Configuration Protocol (DHCP):Ensures clients can obtain IP addresses properly from DHCP servers, validating end-to-end DHCP exchange success and response time.

Address Resolution Protocol (ARP):Verifies correct IP-to-MAC address resolution, confirming that clients can reach devices on the same subnet and that ARP tables are updated correctly.

Marvis Minis also performs checks onDNS resolution, authentication, and application reachability, but not on SNMP or NTP. Those protocols are used for management and time synchronization, not end-user connectivity validation.

Thus, the correct answers areB (DHCP)andD (ARP).

Dynamic Port Configuration (DPC)inJuniper Mist Wired Assuranceallows EX Series switches to automatically assign port profiles, VLANs, and policies to connected devices based on their unique identifiers. This automation simplifies switch management and ensures consistent configurations across distributed networks.

According to theJuniper Mist Wired Assurance Configuration and Dynamic Port Management Guide:

“Dynamic Port Configuration matches connected endpoints using identifiers such as LLDP chassis ID and MAC address to assign the appropriate port profile or VLAN automatically.”

LLDP Chassis ID (C):Identifies the connected device by its LLDP advertisement, often representing a switch, phone, or AP.

MAC Address (D):Provides unique device identification, ensuring precise port and VLAN assignment even when LLDP data is unavailable.

OptionsA (Serial Number)andB (IP Address)are not used for port configuration matching in DPC because they are not always available at the time of link establishment.

Therefore, the correct answers are

C.  

In theJuniper Mist Cloud, aWLAN templateis used to standardize and simplify the configuration of wireless networks across multiple sites. Templates define common wireless parameters, ensuring consistent deployment and easier scalability while reducing configuration errors.

According to theJuniper Mist Wireless Assurance Configuration Guide, WLAN templates contain several configurable elements that define how the wireless network operates, including:

Radio Management (A)This element controlsRF parameterssuch as transmit power, channel width, and radio band assignments (2.4 GHz / 5 GHz / 6 GHz). It leverages Mist’sAI-driven Radio Resource Management (RRM)to optimize RF performance across APs dynamically.

WLANs (D)The template includesWLAN definitions(SSIDs) with associated settings such as authentication type, VLAN assignment, access control policies, and bandwidth limitations. WLANs can be linked to specific sites through these templates for unified management.

The other options are incorrect:

Template Policies (B)are not a defined component within WLAN templates—they refer to higher-level configuration management.

Organizations (C)exist at the top hierarchy level in Mist Cloud (above sites and templates) and are not configured within a WLAN template.

Therefore, the two correct configuration elements available in a WLAN template are:

A.  

Radio management

D.  

WLANs

To create a real-time visualization dashboard that displays clients on a map, use Live View and WebSocket APIs. The "Live View" feature in Juniper Mist provides a graphical, interactive map view of clients (devices) and assets as they move through a site, with location data updated in real time. The Juniper Mist WebSocket API enables developers and integrators to subscribe to client location topics and stream position data directly to custom dashboards. According to the documentation: "WebSockets open a bidirectional communication session for sending and receiving real-time event-driven responses... Useful in circumstances where you want to avoid browser refreshes and display real-time location data." Combining these allows you to build a dashboard showing live client positioning, as seen in sample dashboards and integration guides for Mist.