Free Juniper JN0-460 Practice Exam with Questions & Answers | Set: 3

According to Juniper Networks' EVPN documentation, an EVPN Type 4 route, also known as an Ethernet Segment route, is a critical component of the BGP EVPN control plane used specifically in multihoming scenarios. When a Customer Edge (CE) device is connected to two or more Provider Edge (PE) routers via a Link Aggregation Group (LAG), these PE routers must coordinate to manage traffic flow and prevent network loops.

The primary purpose of the Type 4 route is to enable Designated Forwarder (DF) election. In a multihomed Ethernet Segment (identified by a unique Ethernet Segment Identifier or ESI), only one PE router—the Designated Forwarder—is permitted to forward Broadcast, Unknown unicast, and Multicast (BUM) traffic from the EVPN core to the CE device. Without this election process, multiple PE routers would forward the same BUM packets to the CE, leading to traffic duplication and potential broadcast storms.

The workflow begins when a PE router is configured with an ESI on a physical or logical interface; it then generates and advertises a Type 4 route to all other PE routers in the network. This route carries the ESI and an "ES-import" extended community, which allows other PEs connected to the same segment to automatically discover their peers. Once these "peering" PEs are discovered, they collectively execute a DF election algorithm—such as the default modulo-based algorithm or the newer preference-based algorithm—to select the DF and Backup Forwarder (BDF) for each VLAN or bridge domain. By ensuring a deterministic and synchronized selection of the forwarder, Type 4 routes provide the foundational stability required for active-active and active-standby multihoming in modern campus and data center fabrics.

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.

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.

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.

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.