Important Juniper JN0-460 JNCIS-MistAI-Wired Exam Questions

Answer: A, D

Explanation:

When a switch is claimed into a Mist organization, it appears in one of several states depending on connectivity and site assignment.

''After claiming, switches initially appear asUnassignedif they are not yet linked to a site. Once online and connected to Mist Cloud, they transition toConnectedstatus and begin receiving configurations and telemetry.''

Option A (Connected):Correct--- indicates the switch is online and communicating with Mist Cloud.

Option B (Inactive):Incorrect --- not a valid device state in Mist.

Option C (Active):Incorrect --- ''Active'' is not a device state label in Mist.

Option D (Unassigned):Correct--- indicates the switch has been claimed but not yet assigned to a site.

Juniper Mist AI for Wired -- Device Claiming and State Management Guide

Juniper Mist Cloud -- Switch Onboarding Workflow

Juniper Mist Wired Assurance -- Device Status Descriptions

Answer: A

Explanation:

According to Juniper Networks technical documentation regarding 'Bridging and VLANs,' Layer 2 network segmentation is primarily achieved through the implementation of Virtual Local Area Networks (VLANs). While VLANs provide critical segmentation services by grouping related devices into independent logical networks and containing broadcasts within specific domains, they are bound by the architectural constraints of the IEEE 802.1Q standard.

A fundamental limitation of this traditional Layer 2 approach is the address space of the VLAN identifier. The 802.1Q header allocates exactly 12 bits for the VLAN ID (VID). This mathematical constraint limits the total number of possible VLANs to 4,096 ($2^{12}$). Within the Junos operating system, VLAN IDs 0 and 4,095 are strictly reserved for system internal functions and cannot be assigned to user traffic, resulting in a maximum of 4,094 usable VLANs for network segmentation.

In modern enterprise environments---especially those involving large-scale multitenancy, cloud services, or high-density campus deployments---this 4,094 limit often becomes a significant bottleneck. Network administrators can exhaust this pool when attempting to provide granular isolation for thousands of unique device types, departments, and guest users. To overcome this specific limitation, Juniper recommends moving toward EVPN-VXLAN campus fabrics. VXLAN technology replaces the 12-bit VLAN tag with a 24-bit VXLAN Network Identifier (VNI), which theoretically supports over 16 million unique segments. This vast increase in scalability allows for the creation of administrative domains that far exceed the capabilities of traditional Layer 2 Ethernet bridging. While Layer 2 domains also face challenges related to Spanning Tree Protocol (STP) complexity and large broadcast diameters, the numeric exhaustion of the VLAN ID space remains the most definitive hardware-level limitation of standard Layer 2 segmentation.

Answer: A, C, D

Explanation:

According to Juniper Mist documentation, the EX2300, EX4650, and QFX5120 switches require a specific additional workflow within the Mist portal to form a Virtual Chassis because these models do not have dedicated Virtual Chassis ports (VCPs). Unlike other EX-series models (such as the EX4100 or EX4400) that possess factory-defined, dedicated VCPs and can form a Virtual Chassis automatically upon physical connection, these three platforms require an administrator to explicitly initiate the 'Form Virtual Chassis' action from the Mist UI.

This workflow is necessary because the system must logically convert standard network uplink ports into Virtual Chassis ports to enable stack communication. To execute this, the switches must first be onboarded to the Juniper Mist cloud as standalone devices and assigned to the same site. Once they are online and their configuration is managed by Mist, the administrator selects the desired members from the switch inventory and clicks More > Form Virtual Chassis.

During this additional workflow, the Mist portal prompts the user to specify which front-panel ports will be repurposed as VCPs and allows for the manual assignment of member IDs and Routing Engine roles. This 'pre-provisioned' method ensures a deterministic setup where roles are not left to chance. Once the command is pushed, the switches reboot to reconfigure their internal hardware logic to treat the selected ports as fabric links. Juniper emphasizes that for these specific models, the 'Form Virtual Chassis' option is the only supported way to establish the stack within Wired Assurance, as it ensures that the cloud-native management plane correctly recognizes the multiple physical chassis as a single logical entity.

Answer: D

Explanation:

According to Juniper's Validated Designs (JVD) for campus fabrics, the Campus Fabric IP Clos (often referred to as a 5-stage Clos) is the architecture specifically engineered for high-scale environments supporting 10,000+ users. This design is characterized by extending the EVPN control plane and VXLAN data plane all the way to the access layer. By terminating VXLAN tunnels at the access switch---functioning as a Virtual Tunnel Endpoint (VTEP)---the network can seamlessly support both Layer 2 and Layer 3 devices directly at the edge of the fabric.

The primary driver for choosing IP Clos in large-scale deployments is its superior scalability. In this model, the core switches are shielded from the massive table sizes required to learn thousands of individual endpoint MAC and IP addresses. Instead, core devices only need to maintain reachability to the loopback addresses of the access layer switches. This reduction in the 'flood and learn' pressure on the core is critical as the number of endpoints grows, ensuring that the core can scale far into the future with predictable growth.

Additionally, the IP Clos architecture provides the most flexible environment for microsegmentation using Group-Based Policies (GBP) and macrosegmentation using Virtual Routing and Forwarding (VRF) instances. Since routing occurs at the access device, 'east-west' traffic between local endpoints remains efficient and does not need to traverse the distribution or core tiers. While EVPN Multihoming and Core-Distribution (CRB/ERB) models are effective for smaller sites or brownfield environments where access switches are legacy Layer 2-only devices, only the IP Clos architecture provides the end-to-end VXLAN capability required for high-density, future-proof campus fabrics.

Answer: B, C

Explanation:

According to Juniper Mist documentation, the brownfield adoption process is utilized when bringing existing Juniper switches---which already have a local configuration---under the management of the Mist cloud. This process differs significantly from the greenfield 'claiming' method, as it requires manual interaction with the device's management interface to establish the initial connection2.

A critical requirement for this process is that CLI access to the Juniper cloud-ready switch is required3. To initiate adoption, the administrator must log in to the switch via console or SSH and enter a specific set of Junos OS configuration commands provided by the Mist portal. These commands include the necessary parameters for the switch to establish an outbound SSH connection to the Mist cloud, typically using either TCP port 2200 or 443. Without direct CLI access to paste and execute these adoption strings, the switch cannot register itself with the organization's inventory in the dashboard.

Furthermore, because this process involves modifying the switch's local configuration file to add the Mist management parameters, you must perform a commit on the switch after adding the switch adoption commands7. In the Junos operating system, configuration changes reside in a candidate configuration buffer and do not take effect until a commit operation is successfully executed8. Once committed, the switch initiates the connection to Mist9. If the connection is successful, the switch status in the Mist dashboard will transition from 'Unassigned' to 'Connected,' enabling AI-driven telemetry collection and Wired Assurance monitoring. This adoption method allows for a seamless transition of legacy infrastructure into a modern, cloud-managed environment without requiring a factory reset or the presence of a physical QR claim code.