Pass the Juniper JNCIS-MistAI JN0-460 Questions and answers with ValidTests

According to Juniper Networks' EVPN-VXLAN documentation, devices that perform the encapsulation and de-encapsulation of Ethernet frames into VXLAN UDP packets at the edge of the network are known as Virtual Tunnel Endpoints (VTEPs)1111. In the context of a campus fabric overlay, these devices often function as L2 gateways when they bridge traditional Layer 2 traffic from end-user devices across a Layer 3 IP fabric.

The exhibit demonstrates a 3-stage IP Clos architecture where access1 and access3 are explicitly identified as VTEP endpoints. A VXLAN tunnel is shown originating at access1 and terminating at access3, allowing "User1" and "Server1"—both located on the same 10.1.1.0/24 subnet—to communicate as if they were on the same physical Layer 2 segment despite being separated by a Layer 3 IP Fabric (172.16.0.0/24). In this scenario, access1 and access3 fulfill the L2 gateway role by mapping the local VLAN traffic to a specific VXLAN Network Identifier (VNI) for transport across the underlay3.

As L2 gateways, these switches maintain the bridge table for the overlay network, learning MAC addresses from local ports and via the EVPN control plane from remote VTEPs4. This architecture allows for seamless Layer 2 mobility and connectivity across complex routed infrastructures while eliminating the need for Spanning Tree Protocol (STP) in the core5555. In contrast, options like "VNI" refer to the segment ID itself rather than a device role, and "root bridge" refers to an STP-specific role that EVPN-VXLAN is designed to move away from in a modern fabric.

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 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.

Group-Based Policy (GBP)is a Juniper EVPN-VXLAN feature that enablesmicrosegmentationwithout requiring multiple VRFs or VLANs. It is implemented within Juniper Mist’sWired Assurance and Campus Fabricframeworks.

“GBP provides scalable, identity-based segmentation for campus fabrics and is supported on EX4100 and EX4400 Series switches operating in EVPN-VXLAN mode under Mist management.”

The feature requires hardware and software support forEVPN-VXLAN and GBP tagging, which is currently available on specific EX models managed by Mist Cloud.

Option A:Correct— GBP requires compatible access switches, specifically EX4100 and EX4400 models.

Option B:Incorrect — GBP is centrally managed through Mist Cloud, not configured per switch.

Option C:Incorrect — GBP is provisioned via Mist Cloud, not the CLI.

Option D:Incorrect — GBP is not supported onallEVPN-capable switches; only on defined platforms (EX4100/EX4400).

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

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

InJuniper Mist AI for Wired, configuration templates are a foundational part ofswitch onboarding and management. The primary purpose of these templates is to ensure configuration consistency across all switches that belong to a specific site or organization.

“Switch configuration templates allow administrators to define a standard configuration that is automatically applied to all switches within a site or organization, ensuring consistency and reducing configuration errors.”

Templates can contain base configuration parameters such as NTP, syslog, VLANs, port profiles, and authentication settings. When new switches are onboarded to the Mist Cloud, they automatically inherit the template’s configuration, ensuring uniform behavior across the network fabric.

Option Ais incorrect — templates do not directly impact hardware performance.

Option Bis incorrect — templates are not related to upgrade times.

Option Cis incorrect — templates are used for uniformity, not for switch-specific changes.

Option Dcorrectly describes their main benefit —ensuring consistent configuration across all switches.

Juniper’s official Campus Fabric IP Clos designfor Mist Wired Assurance defines that the3-stage IP Clostopology eliminates the traditionaldistribution layerentirely. This architecture is intended for smaller campus environments that do not need an intermediate distribution layer between the access and core.

“Juniper’s Wired Assurance supports 3-Stage and 5-Stage IP Clos deployments. The 3-Stage IP Clos is targeted towards deployments that do not require a Distribution Layer and have smaller scale requirements.”

Because the distribution layer is not present, the only hierarchical connection in a 3-stage campus fabric is between thecore and access layers. Traffic is routed directly at the access layer, and each access switch acts as a Layer-3 gateway (IRB) for its VLANs.

“In a campus fabric IP Clos architecture, Mist provisions Layer-3 (L3) integrated routing and bridging (IRB) interfaces on the access layer. All the access switches are configured with the same IP address for each L3 subnet.”

Additionally, the Juniper documentation explains that point-to-point links are configuredbetween layers, and in the case of the 3-stage design (with no distribution), this means between thecore and accessdevices:

“The point-to-point links between each layer utilize /31 addressing to conserve addresses.”

Therefore, the correct statement isC: The core layer is connected to the access layer.

OptionsAandBincorrectly mention a distribution layer that does not exist in this topology.

OptionDis incorrect because core (spine) devices in a Clos fabric are not interconnected with each other.

Comprehensive and Detailed Explanation From Exact Extract:

InEVPN-VXLANarchitectures, theVXLAN Tunnel Endpoint (VTEP)is the logical interface responsible for encapsulating and de-encapsulating Layer 2 Ethernet frames into VXLAN packets.

Each participating switch — typically the access or distribution node — hosts aVTEPthat maps local VLANs to VXLAN Network Identifiers (VNIs).

When a packet leaves a local VLAN, the VTEP encapsulates it in a VXLAN header and routes it through the underlay IP fabric.

When received at the destination VTEP, the frame is de-encapsulated and delivered to the appropriate local VLAN.

“VTEPs in an EVPN-VXLAN campus fabric perform MAC-to-VNI mapping and encapsulate/decapsulate traffic between virtualized network segments, allowing seamless Layer 2 and Layer 3 connectivity across an IP underlay.”

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.

TheAlerts Configurationsection in the Mist dashboard allows administrators to definenotification rules and recipientsfor various network events, including switch issues, site-level incidents, and SLE threshold violations. Notifications can be sent viaemail, webhook, or third-party integrations.

“Use the Alerts Configuration page to enable alerts for specific device events, assign severity levels, and define e-mail or webhook recipients for switch and site notifications.”

Option A (Marvis conversational interface):Used for querying issues via AI, not for email alerts.

Option B (Wired SLEs):Provides analytics and thresholds but does not manage notifications.

Option D (Marvis Actions):Offers suggested remediation steps, not alert setup.

Option C (Alerts Configuration):Correct— this is where email notifications are configured.