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

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.

According to Juniper Mist documentation regarding campus fabric design, the campus fabric IP Clos (also known as a 5-stage Clos) is the architecture that extends the EVPN-VXLAN protocol stack from the core tier down through the distribution tier and finally to the access tier. In this model, every switch in the hierarchy—from the high-capacity core switches to the wiring closet access switches—participates in the EVPN control plane and VXLAN data plane.

By extending EVPN-VXLAN to the access tier, the IP Clos architecture provides a standards-based, scalable framework that allows for seamless Layer 2 connectivity over a Layer 3 underlay across the entire campus333333333. This enables advanced features like Microsegmentation using Group-Based Policies (GBP) and Macrosegmentation via Virtual Routing and Forwarding (VRF) instances directly at the edge of the network.

In contrast, other architectures like "core-distribution" (either CRB or ERB) typically limit the EVPN-VXLAN fabric to the core and distribution layers, leaving the access tier to connect via traditional methods like LAG, Virtual Chassis, or standard Layer 2 trunks5555. The IP Clos architecture is specifically designed for large-scale deployments where high density, vendor interoperability, and end-to-end policy enforcement are critical6. By utilizing a 5-stage IP Clos, organizations can eliminate the complexities of Spanning Tree Protocol (STP) while maintaining a flexible, "any-to-any" communication path throughout the physical infrastructure.

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.

Marvis is Juniper’s Virtual Network Assistant (VNA) that leverages AI to provide natural language queries, anomaly detection, and proactive troubleshooting across wireless, wired, and WAN networks.

“Marvis, the AI-driven Virtual Network Assistant, requires a Virtual Network Assistant subscription. The subscription enables Marvis to provide insights, recommendations, and natural language queries for Mist-managed networks.”

Option A (Access Assurance) is related to NAC/802.1X enforcement.

Option B (IoT Assurance) applies to profiling and securing IoT devices.

Option D (Wired Assurance) enables switch telemetry, onboarding, and assurance, but does not unlock Marvis.

Option C (Virtual Network Assistant) is correct — this subscription is required to enable Marvis AI.

According to theJuniper Mist AI for Wired – Campus Fabric IP Clos Deployment Workflow, deploying a campus fabric involves a defined sequence of planning and configuration steps within the Mist Cloud interface. The key stages include:

“To deploy a campus fabric, you must first define the topology type, identify the physical connections between devices, and define the networks of interest that will be extended across the fabric.”

Breaking this down:

Choose the topology (D):Selecting the correct fabric type (3-Stage or 5-Stage IP Clos) determines how access, distribution, and core switches will interconnect.

Define the physical connections (A):This step involves specifying the uplink and downlink relationships between switches so that Mist can auto-generate EVPN-VXLAN and routing configurations.

Define the networks of interest (B):These are the VLANs and subnets that need to be extended across the fabric for user and device connectivity.

Steps such asconfiguring DNS serversordefining GBP tagsarenot part of the campus fabric deployment workflowin Mist Wired; they are optional or separate configurations outside the main deployment flow.