The JNCIS-MistAI-Wired (JN0-460)

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.

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 Mist documentation, the Throughput Service Level Expectation (SLE) is the primary metric used to represent the ability of wired users to pass traffic across the network without impedance. This SLE provides a comprehensive oversight of network performance by identifying issues that degrade the user experience, such as storm control events, interface anomalies, and specifically uplink congestion .

Within the Throughput SLE, the Congestion classifier (also referred to as Congestion Uplink ) is specifically designed to monitor for buffer saturation and packet drops (TxDrops). When traffic arriving at an interface exceeds its processing or forwarding capacity, packets are queued in a buffer; if this buffer becomes full, the switch begins dropping packets. Juniper Mist utilizes a specific formula considering the ratios of TxDrops to TxPackets, Transmitted bps to Link Speed, and Received Speed to Link Speed to determine if a " Bad User Minute " has occurred due to congestion.

A critical feature of Wired Assurance is the automatic identification of uplink interfaces . Mist identifies these high-capacity ports by analyzing switch telemetry for characteristics such as having a switch or router as an LLDP neighbor, being designated as a Spanning Tree Protocol (STP) root port, or exhibiting significantly higher packet counts compared to access ports. When congestion is detected on an interface identified as an uplink, the system recognizes that this bottleneck impacts every user on that switch. By correlating these drops with the Throughput SLE, network administrators can proactively identify when a site requires more bandwidth or a different fabric architecture to handle current traffic demands, rather than simply monitoring if the link is physically " up " or " down " .

WhenMarvis Actionsdisplay “AI Validated,” it indicates the issue was detected earlier but is nowresolved.

Marvis automatically validates remediation and marks the action closed once the anomaly clears.

ThePost-Install (Installer)role has minimal access—sufficient only toclaim APs or switches, assign or unassign them, and place them on maps.

It cannot unclaim or remove devices and typically expires after installation.

Dynamic Port Configuration (DPC)in Juniper Mist enablesautomatic switch port configurationbased on connected device type (e.g., phones, access points, printers). When setting up DPC, administrators define thematching criteria(such as MAC OUI or LLDP system name) and associate aConfiguration Profilethat determines which settings are applied.

“To configure Dynamic Port Configuration, you must assign the ports where DPC will run and select the configuration profile that defines how the port will be automatically configured when a matching device is detected.”

Option A:Correct— you must select the configuration profile to apply once the device type matches.

Option B:Incorrect — DPC does not use polling; it reacts to real-time LLDP/device discovery.

Option C:Correct— you must assign the ports on which DPC operates.

Option D:Incorrect — DPC is supported across EX models running compatible firmware but does not require manually setting a Junos version in configuration.

Creating a new site requires asite nameandtime zone.

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

In Juniper Mist campus fabric architectures, thelocation of the Layer 3 gateway (IRB interface)differentiatescentrally-routed bridging (CRB)fromedge-routed bridging (ERB):

InCRB, thegateway resides at the core layer— routing occurs centrally, and access/distribution layers perform Layer 2 bridging.

InERB, thegateway moves to the edge (distribution layer), enabling routing to occur closer to endpoints, improving performance and scalability.

“In a centrally-routed bridging (CRB) topology, Layer 3 gateways reside at the core. When transitioning to an edge-routed bridging (ERB) design, the Layer 3 gateways are moved to the distribution layer, closer to the access switches and clients.”

Therefore, when moving from acore-distribution CRBto anERBmodel, thegateway moves from the distribution to the access layerin campus terms (edge = access).

Option A:Incorrect — ERB gateways are not at the distribution layer only.

Option B:Incorrect — opposite direction.

Option C:Correct— the gateway movesfrom distribution to access (edge).

Option D:Incorrect — this describes CRB, not ERB.

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 connection 2 .

A critical requirement for this process is that CLI access to the Juniper cloud-ready switch is required 3 . 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 commands 7 . In the Junos operating system, configuration changes reside in a candidate configuration buffer and do not take effect until a commit operation is successfully executed 8 . Once committed, the switch initiates the connection to Mist 9 . 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 .