JN0-460 JNCIS-MistAI-Wired Questions and Answers

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.

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.

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.

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.

Link Layer Discovery Protocol (LLDP)is a Layer 2 discovery protocol that allows network devices to advertise identity and capabilities to directly connected neighbors. While LLDP is useful for basic topology discovery, it has two key limitations inWired Assurance client identification:

“LLDP operates at Layer 2 between directly connected devices and must be explicitly enabled on all participating network elements to provide neighbor information. It cannot discover devices beyond the first physical hop.”

Option A:Correct— LLDP must beconfigured and enabledon each network device to function.

Option B:Incorrect — LLDP itself is scalable but limited to direct adjacency.

Option C:Correct— LLDP only worksbetween directly connected devices.

Option D:Incorrect — not all clients support LLDP; however, the question asks forlimitations of using LLDP, not lack of support.

Aport negotiation mismatchoccurs when the local and remote interfaces fail to agree on common speed or duplex settings.

Marvis Wired Assurance automatically detects this by analyzing telemetry from the switch’s physical interfaces.

You can resolve this by ensuringauto-negotiationis enabled on both ends (A) and verifying the peer device supports the802.3 autonegotiation standard(D).

Manually forcing half-duplex or replacing hardware is unnecessary unless the hardware is faulty.

“Marvis Wired Actions correlate interface negotiation errors with LLDP neighbor data to pinpoint mismatched configurations, helping administrators quickly verify speed/duplex compatibility and 802.3 autonegotiation support.”

During campus fabric deploymentin Mist AI, switches are onboarded usingclaim codesand must beassigned to the correct siteandonlineso that Mist can push configurations and validate connectivity.

“All switches to be included in a campus fabric must be claimed, online, and assigned to the target site before launching the Campus Fabric wizard. Mist Cloud automatically discovers their roles and builds the topology.”

Option A:Incorrect — switches must be site-assigned before fabric creation.

Option B:Correct— switches must beonlineto receive configurations from Mist.

Option C:Incorrect — offline devices cannot be configured or validated in the fabric wizard.

Option D:Correct— switches must beassigned to the correct sitefor topology creation.

ForJuniper cloud-ready EX Series switches(EX2300, EX3400, EX4100, EX4400, etc.) to successfully onboard to theJuniper Mist Cloud, specific connectivity requirements must be met:

“Cloud-managed EX switches require outbound connectivity to the Mist Cloud on TCP ports 2200 or 443. Switches must also have access to DNS services to resolve cloud service URLs during onboarding.”

Option A:Incorrect — minimum version depends on switch model; older models may onboard with earlier releases (e.g., 20.x, 21.x).

Option B:Correct— outbound TCP 2200 or 443 connectivity is required for cloud registration.

Option C:Incorrect — switches connect directly to Mist Cloud, not the Agile Licensing Portal.

Option D:Correct— DNS resolution is mandatory for discovering Mist Cloud endpoints.

Juniper Wired Assurance licensingis based on switch port count and supports a range of hardware platforms. Subscriptions are available for12-port,24-port, and48-portmodels across the EX Series portfolio.

“Wired Assurance subscriptions are available for all supported EX Series switches in 12-port, 24-port, and 48-port license options, aligning to switch hardware configurations.”

Option A:Incorrect — 24-port only does not cover all options.

Option B:Incorrect — 12- and 24-port licenses exist, but 48-port is also supported.

Option C:Correct— Mist supports12-, 24-, and 48-portsubscription tiers.

Option D:Incorrect — 12-port alone is incomplete.

In theJuniper Mist AI for Wired dashboard, administrators can select one or more switch ports (as shown in the exhibit, e.g., port ge-0/0/25 on an EX4100-48MP). Once configuration changes are made — such as VLAN assignment, port profiles, PoE settings, or administrative state — theSave buttonmust be clicked to confirm and apply those changes to the device.

“When making configuration changes in the Mist switch interface, the Save button must be used to confirm the modifications. Clicking Save applies the selected port settings to the switch through Mist Cloud.”

Option Ais incorrect: saving does not create a backup. Backups and snapshots are handled through Mist’s configuration archive, not via the Save button.

Option Bis incorrect: Save does not reset configuration; instead, it commits changes.

Option Cis incorrect: there is no preview function tied to Save.

Option Dis correct: the Save button is explicitly forapplying configuration changesto the selected switch or port(s).

According to Juniper Mist documentation, the term " Adopting a Switch " specifically refers to the process of bringing an existing, already-configured switch—often termed a brownfield device—under the management of the Juniper Mist cloud. This is distinct from the " claiming " process, which is reserved for greenfield environments where new, factory-default switches are added using a QR code or activation code.

In a brownfield scenario, the switch is typically already in production or has a pre-existing local configuration that must be preserved or integrated into the Mist AI-driven dashboard. To adopt such a switch, the administrator must manually interact with the switch ' s Command Line Interface (CLI). The Mist portal provides a unique adoption command —a string of Junos OS configuration—that includes the specific URL for the Mist cloud and the organization’s unique registration token. Once this command is pasted into the switch ' s CLI and committed, the switch initiates an outbound connection to the Mist cloud via TCP port 2200 or 443.

Upon successful connection, the switch ' s status changes from " Unassigned " to " Connected " in the Mist dashboard. This transition allows the Mist AI engine to begin collecting telemetry, monitoring Service Level Expectations (SLEs), and performing automated troubleshooting. While the adoption process allows for " monitoring only " mode to avoid disrupting existing services, it is the fundamental first step for transitioning legacy Juniper infrastructure into a modern, cloud-managed Wired Assurance environment. This workflow is essential for organizations looking to leverage Marvis AI and automated operations without having to factory-reset their entire existing network.

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.

InEVPN-VXLAN,BUM (Broadcast, Unknown unicast, and Multicast)traffic is handled differently than unicast traffic. EVPN provides two main forwarding mechanisms to distribute BUM traffic betweenVTEPs(VXLAN Tunnel Endpoints):

“BUM traffic in EVPN-VXLAN fabrics is replicated using eitheringress replicationorunderlay multicast(PIM-based). Both methods ensure that broadcast and unknown unicast frames reach all remote VTEPs within the same VXLAN segment.”

Option A:Incorrect — static routes are unrelated to BUM forwarding.

Option B:Incorrect — BGP is thecontrol plane, not a data-plane forwarding method.

Option C:Correct—Ingress replicationreplicates BUM packets to all remote VTEPs in the same VNI using unicast tunnels.

Option D:Correct—Underlay replication (multicast)uses multicast groups in the IP underlay to distribute BUM frames efficiently.

Juniper Mist uses open, cloud-native APIs to providereal-time telemetry and integration.

Data is collected and streamed from the backend using:

RESTful APIs– for configuration, automation, and reporting.

Webhooks– to push events, alerts, or SLE changes to third-party systems.

In Juniper Mist Cloud, there are multiple configuration scopes:

Organization-level templatesapply globally.

Site-level configurationapplies across all devices in a site.

Individual switch configurationis used to define unique, device-specific attributes such ashostname, management IP, or local overrides.

“Templates and site-level configuration ensure consistency across devices, whileindividual switch configuration is used to assign unique values such as hostnames.”

Option A:Incorrect — org templates define common config, not hostnames.

Option B:Incorrect — site configs are shared across all switches in the site.

Option D:Incorrect — device profiles apply settings like port policies or authentication, not hostnames.

Option C:Correct —individual switch configurationis the correct place to assign hostnames uniquely per device.

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 switch 1 . 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 issue 2 . 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.

In Juniper Mist,Greenfield adoptionapplies to new, cloud-ready switches (such as EX4100, EX4400, and QFX series) using aclaim or activation codeto securely connect to the Mist cloud.

Brownfield adoption, however, supports switches already deployed or not factory-fresh. These are manually onboarded by configuring outbound management connectivity and adopting them through the Mist portal.

This distinction enables both new and legacy EX/QFX environments to be cloud-managed under Wired Assurance.

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.

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

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

In anEVPN-VXLAN fabric, thecontrol planeoperates overBGP EVPNand is responsible for distributing endpoint reachability information (MAC and IP) among VTEPs. Thedata plane, by contrast, performs encapsulation and forwarding.

“The EVPN control plane uses BGP to exchange MAC and IP address reachability information between VTEPs, enabling efficient forwarding and loop prevention without relying on flood-and-learn behavior.”

Option A:Incorrect — encapsulation occurs in thedata plane, not the control plane.

Option B:Correct — the control plane distributesMAC-to-VTEP mappings.

Option C:Correct — the control plane also distributesIP-to-MAC associations(Type 2 and Type 5 EVPN routes).

Option D:Incorrect — the control plane does not alter packet headers.

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, 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.