JN0-460 JNCIS-MistAI-Wired Questions and Answers

In Mist,sitesrepresent the physical or logical grouping of devices within an organization.

You create and manage a site configuration under theLocationhierarchy in the Mist UI.

Each site inherits organization-level settings but can override or customize specific configurations such as VLANs, templates, or switch settings.

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.

Mistwebhooksprovide real-time integration with external systems by streamingalertsandSLE (client) metrics.

They allow automation tools to react immediately to network health or performance changes.

Marvis, the AI-driven virtual network assistant in Mist, provides real-time troubleshooting insights for both wired and wireless devices.

When used withWired Assurance, certain actions require Juniper EX or QFX switches for telemetry collection.

Two of these wired-specific actions are:

Bad Cable Detection– triggered when electrical faults or poor cable quality are observed through LLDP or physical diagnostics.

When a switch is successfully onboarded into Mist Cloud but shows“Unassigned,”it means the device has been claimed into the organization but hasnot yet been assigned to a specific site.

“After claiming switches into an organization, you must assign each switch to a site for it to transition from Unassigned to Connected state and begin receiving configuration and telemetry updates.”

Option A:Incorrect — rescanning is not needed once the device is claimed.

Option B:Incorrect — reboots are unnecessary for assignment recognition.

Option C:Incorrect — these commands are for connectivity troubleshooting, not site assignment.

Option D:Correct— assigning each switch to itsintended siteenables full Mist management and connectivity state.

Juniper Mist AI collectstelemetry for Service Level Expectations (SLEs)across wired and wireless devices. This telemetry includes metrics such as time-to-connect, throughput, coverage, and switch performance.

“Service Level Expectation (SLE) data is collected from every device and stored for up toone monthin the Mist Cloud. This allows administrators to analyze historical performance trends and troubleshoot issues based on real-time and historical data.”

Option B (2 months):Incorrect — data is not retained this long.

Option C (7 days):Incorrect — telemetry retention is longer.

Option D (24 hours):Incorrect — too short for Mist SLE analytics.

Option A (1 month):Correct — Mist Cloud retains SLE telemetry for30 days (1 month).

According to Juniper Mist documentation, Wired Service Level Expectations (SLEs) are designed to provide operational visibility into the wired experience by monitoring Juniper EX and QFX Series switches. These SLEs leverage pre-connection and post-connection performance metrics to ensure network reliability and performance.

Pre-connection metrics are specifically focused on the initial phase of a client's journey to join the network. These metrics show the total number and the time required for successful connects and authentication. By tracking 802.1X events and DHCP snooping data, Mist can identify if clients are failing to onboard due to RADIUS issues, authentication timeouts, or failures in the DHCP binding process. This allows administrators to proactively address onboarding hurdles before they impact the broader user base.

Post-connection metrics, conversely, measure the network experience once a client is already "on the wire" and attempting to pass data. These metrics primarily measure throughput and focus on detecting various network errors and operational anomalies. Specifically, post-connection monitoring detects issues such as Spanning Tree Protocol (STP) loops, interface errors, and congestion. Additional post-connection insights include identifying cable issues, negotiation failures, and MTU mismatches that might occur during active data transmission.

In summary, Juniper Mist divides its telemetry into these two distinct categories to simplify troubleshooting. Pre-connection metrics ensure that users can get on the network, while post-connection metrics ensure that the network can sustain their traffic requirements without errors. This combined approach enables the Mist AI-driven Predictive Analytics and Correlation Engine (PACE) to provide a holistic view of the end-user experience, moving beyond traditional "up/down" monitoring to a deeper understanding of the quality of the client experience.

EVPN, when used with VXLAN, leveragesBGP MPLS/VXLAN control plane mechanisms. To prevent overlapping IP prefixes between different tenants or sites, EVPN uses aRoute Distinguisher (RD).

“In EVPN-VXLAN, the route distinguisher (RD) makes routes unique when overlapping IP prefixes or MAC addresses are advertised between multiple tenants or sites.”

Option A(designated forwarder) applies to multi-homing in EVPN, not prefix uniqueness.

Option B(Layer 2 gateway) does not prevent IP overlap; it bridges VLANs.

Option D(ESI) is used for identifying multi-homed Ethernet segments, not to differentiate overlapping subnets.

Option C(Route Distinguisher) is correct, as it uniquely identifies routes even if the IP addresses are the same across sites.

Juniper Mist automatically classifies ports to simplify visibility and automation withinWired Assurance. The Mist cloud analyzesport telemetryandlink behaviorto determine port roles, including uplinks.

“Mist uses machine learning and switch telemetry to automatically detect uplinks by analyzing traffic behavior and topology information. Uplink ports typically exhibit higher TX/RX utilization and are identified as spanning-tree root or forwarding ports connecting upstream devices.”

Option A:Correct — Mist examines traffic statistics. Ports with significantly higher TX/RX utilization relative to others are likely uplinks.

Option B:Incorrect — MTU size is not a classification criterion.

Option C:Correct — Mist usesSTP information(root or designated port status) to identify uplinks.

Option D:Incorrect — port description fields are for administrative purposes only and are not used by Mist analytics.

According to Juniper documentation, a route distinguisher (RD) is a critical address qualifier used to ensure that network layer reachability information (NLRI) remains unique within a Multiprotocol BGP (MP-BGP) control plane, especially in multitenant environments. In a service provider network, different tenants may use identical, overlapping private IP address spaces (such as 192.168.1.0/24). If these routes were advertised without a qualifier, BGP—which typically only considers the IP prefix—would treat them as the same route and potentially overwrite one with the other based on standard BGP best-path selection.

The route distinguisher solves this by prepending an 8-byte field to the tenant's IP address, effectively transforming a 32-bit IPv4 prefix into a unique 96-bit VPN-IPv4 address. This 8-byte value is typically configured in formats such as as-number:number or ip-address:number. Because the resulting VPN-IPv4 prefix is unique to that specific routing instance, the service provider's BGP infrastructure can carry and distinguish between overlapping routes from multiple customers simultaneously.

It is important to differentiate the RD from a route target (RT). While the RD's sole purpose is to provide uniqueness so that routes are not discarded or overwritten, the route target is an extended community attribute used to control the import and export of these routes into the correct virtual routing and forwarding (VRF) tables on remote PE routers. In Juniper's Junos OS, each routing instance of type vrf or evpn must have a unique RD associated with it; failing to configure a unique RD or attempting to use the same RD across different instances will result in a configuration commit failure. This fundamental separation of "making routes unique" (RD) and "directing routes to the right place" (RT) allows for the scalable, isolated multitenancy required in modern EVPN-VXLAN campus and data center fabrics.

TheMist UI(User Interface) is Juniper’s cloud-based management platform used tomanage both wired and wireless devices, including EX, QFX, and SRX platforms.

It provides centralized visibility, configuration, analytics, and AI-driven insights for the entire enterprise network infrastructure.

WithinWired Assurance, the Mist UI enables device claiming, switch templates, configuration management, and SLE monitoring.

Creating a new site requires asite nameandtime zone.

Other parameters (like templates or location data) are optional but recommended for proper reporting.

According to Juniper Mist documentation, Dynamic Port Configuration (DPC)—also referred to as Dynamic Port Profiles—is the feature specifically designed to automate the assignment of VLANs and port settings based on the type of device connected to a switch. This technology enables the concept of "colorless ports," where any device (such as a Juniper Mist Access Point, an IP camera, or a VoIP phone) can be plugged into any available switch port without prior manual configuration.

The system functions by using "port assignment rules" that leverage various device properties to identify the connected hardware. These properties include LLDP attributes (System Name, Chassis ID, or Description), MAC addresses (including specific OUI ranges), and RADIUS attributes. For example, a rule can be configured to detect an LLDP System Description starting with "Mist Systems" and automatically apply a "Wireless AP" port profile. This profile typically includes the management VLAN, PoE settings, and Spanning Tree Protocol (STP) parameters required for an access point to function.

The primary benefit of DPC is the reduction of manual labor and the elimination of configuration errors in large-scale deployments. In traditional environments, an administrator would have to manually assign a VLAN to a specific physical port; with DPC, the Juniper Mist cloud detects the device and pushes the relevant configuration to the switch in real-time. If the device is disconnected, the port can be configured to revert to a "restricted" or "guest" VLAN, ensuring that the network remains secure against unauthorized access. This AI-driven approach drives consistency across multiple sites while significantly streamlining the onboarding of new hardware.

In Juniper Mist role-based access control (RBAC),site-level administratorshave limited privileges to manage devices within their assigned sites.

They cannot modify organization-level templates or global settings but can performoperational tasks, includingrebooting APs or switchesand monitoring their status.

This ensures proper delegation of duties while maintaining centralized configuration control.

According to Juniper Mist documentation, the Throughput Service Level Expectation (SLE) is the primary metric used to measure the ability of wired clients to pass traffic across the physical network without impedance. This SLE is critical for diagnosing issues with real-time, high-bandwidth applications such as video streams, which are highly sensitive to packet loss and latency. Within the Throughput SLE, the Storm Control classifier is specifically designed to identify "bad user minutes" caused by the suppression of Broadcast, Unknown Unicast, and Multicast (BUM) traffic.

Storm control is a mechanism that enables the switch to monitor traffic levels and drop BUM packets when a specified traffic level—known as the storm control level—is exceeded. This prevents a "traffic storm" from proliferating and degrading the overall performance of the LAN. While this is a vital security feature to prevent network meltdowns, it can inadvertently impact legitimate traffic. For instance, if multicast-based video streams or other heavy BUM traffic exceed the configured bandwidth percentage on a port, the switch will drop those packets to protect the rest of the network.

When troubleshooting video stream issues, network administrators should inspect the Storm Control classifier to see if it is triggering "bad user minutes". If the Mist dashboard indicates failures under this classifier, it signifies that the switch hardware is actively dropping packets because the BUM traffic limit has been reached. This provides immediate root-cause evidence, allowing the administrator to determine if they need to adjust the storm control thresholds within the Port Profile or investigate the source of the excessive broadcast traffic. By correlating these hardware-level events with the end-user experience, Mist AI simplifies the resolution of complex performance problems that traditional "up/down" monitoring would miss.

According to Juniper Mist documentation, Switch Insights is the dedicated diagnostic and auditing feature within the Mist AI dashboard that provides a granular, chronological record of all events pertaining to a specific switch1. While Site Events or Site Alerts provide a broad overview of health and anomalies across an entire location, Switch Insights is specifically designed for device-level deep dives. When a user navigates to the Insights page for a particular switch, they are presented with a comprehensive timeline that correlates telemetry data with specific system occurrences.

This feature displays a detailed list of Switch Events, including but not limited to interface state transitions (Up/Down), Spanning Tree Protocol (STP) role changes, LLDP neighbor updates, and PoE controller status. Importantly, Switch Insights also tracks administrative actions, such as configuration commits and software upgrades, allowing an administrator to see exactly when a change was made and if that change coincided with a performance degradation in the Wired Service Level Expectations (SLEs).

Beyond simple logging, Switch Insights allows for retroactive troubleshooting. By adjusting the time slider, an administrator can go back in time to review the exact state of the switch during a reported issue2. For example, if a user reports a video conferencing issue that occurred three hours ago, the administrator can use Switch Insights to see if any port flaps, storm control events, or configuration changes took place during that specific window. This AI-driven visibility eliminates the need for manual syslog analysis or persistent CLI monitoring, providing a transparent and easily accessible audit trail for all switch-specific activity within the managed organization.

Anorganization-level configuration templatecan only be applied tosite groups, not to individual sites.

Therefore, a single site such as Site A cannot be directly specified inside an org-level template.

According to Juniper Networks' validated designs for campus fabrics, the campus fabric core-distribution with edge-routed bridging (ERB) is the optimal architecture when high volumes of east-west traffic are present and access switches are restricted to Layer 2 operations. In an ERB design, the EVPN-VXLAN fabric extends from the core switches to the distribution switches.1 The critical differentiator is the placement of the default gateways (Integrated Routing and Bridging or IRB interfaces). In the ERB model, these gateways are moved from the core to the distribution layer, which effectively acts as the "edge" of the EVPN fabric.

By placing the Layer 3 gateways at the distribution layer, inter-VLAN (east-west) traffic is routed closer to the endpoints.2 This prevents the "hairpinning" effect found in Centrally-Routed Bridging (CRB) architectures, where traffic must travel all the way to the core layer to be routed between subnets before returning down to the distribution and access layers. This reduction in latency and core-link utilization is essential for modern campus environments with high server-to-server or client-to-client traffic patterns.

Furthermore, this architecture specifically accommodates Layer 2 access switches. In the ERB core-distribution model, the access switches are not part of the EVPN-VXLAN overlay; instead, they connect to the distribution tier using standard Link Aggregation Control Protocol (LACP) or ESI-LAG. This allows organizations to leverage existing legacy or lower-tier access switches that do not support advanced VXLAN capabilities while still benefiting from a robust, scalable EVPN-VXLAN fabric at the distribution and core layers.5 In contrast, while the campus fabric IP Clos also excels at handling east-west traffic, it requires the access switches themselves to perform VXLAN encapsulation/decapsulation (acting as VTEPs), which contradicts the requirement for access switches to operate only at Layer 2.

In theCampus Fabric Deployment Wizard, the first step is defining thetopology type(3-stage or 5-stage IP Clos) and mapping thephysical connectionsbetween devices (core, distribution, and access).

“The first step in the campus fabric deployment process is to define the topology and identify physical connections between devices. This ensures correct port mapping between core, distribution, and access tiers.”

Option A:Correct— topology definition and physical connectivity mapping occur in the initial step.

Option B:Incorrect — the underlay network configuration happens after topology definition.

Option C:Incorrect — overlay configuration handles EVPN/VXLAN and routing setup, not physical cabling.

Option D:Incorrect — applying intent finalizes the deployment but does not define connectivity.

Route targets (RTs)are extended BGP communities used inMultiprotocol BGP (MP-BGP)forEVPN-VXLANto control route import/export between VRFs.

“A route target identifies the VRF instances that should import or export specific MP-BGP routes. It enables the association of EVPN routes with particular VRFs in multi-tenant environments.”

Option A:Incorrect — EVPN family support is identified through BGP capabilities, not RTs.

Option B:Incorrect — that’s handled by BGP EVPN negotiation, not route targets.

Option C:Correct— route targets definewhich VRFs import/export BGP routes.

Option D:Incorrect — RTs can be manually configured and reused where necessary.

According to Juniper Networks' documentation on campus fabric and EVPN-VXLAN architectures, a Virtual Routing and Forwarding (VRF) instance—conceptually referred to within the Junos OS as a routing instance—is typically used to provide macro-segmentation by logically separating a single physical network into multiple, isolated virtual networks.2 In the context of a modern campus fabric managed by Juniper Mist, VRFs allow network administrators to create distinct routing domains that maintain their own independent routing and forwarding tables.3

This separation is essential for multitenancy and security.4 For example, an organization might use one VRF for "Corporate_IT" and another for "Guest_WiFi" or "IoT_Devices". Because each VRF operates with its own routing table, traffic belonging to one instance is completely isolated from traffic in another by default; packets cannot travel between VRFs unless an administrator explicitly configures "route leaking" or directs the traffic through a stateful firewall for security inspection. This architectural approach also permits the use of overlapping IP address spaces, as the routing decisions for one tenant do not interfere with the address entries of another.5

In a Juniper Mist-driven campus fabric (such as Core-Distribution or IP Clos), the Mist portal streamlines the creation of these VRF instances as part of the fabric workflow.6 Once a VRF is created, specific VLANs (and their corresponding IRB interfaces) are assigned to it, ensuring that Layer 3 gateways are placed in the correct logical domain. While the underlay network (Option D) is responsible for providing the physical reachability (loopback to loopback) between switches using a protocol like eBGP, the overlay network leverages VRFs to deliver the actual isolated user services.

InJuniper Mist Wired Assurance, SLEs (Service Level Expectations) measure key performance indicators for wired network quality.Throughput SLEmonitorsdata transfer quality, includinglatency, jitter, and packet loss, which directly impact real-time applications such as voice or video.

“The Throughput SLE provides visibility into end-to-end network performance by tracking latency, jitter, and packet loss, helping identify congestion or quality issues across wired connections.”

Option A (Throughput):Correct— this SLE includes jitter measurement.

Option B (Successful Connect):Tracks client connection success rate, not jitter.

Option C (Capacity):Monitors link utilization and load, not jitter.

Option D (Switch Health):Monitors device hardware and software health, not traffic performance.