Pass the Juniper JNCIS-DC JN0-480 Questions and answers with CertsForce

According to the Juniper documentation1, an interface map is a configuration template that maps interfaces between logical devices and physical hardware devices (represented with device profiles) while adhering to vendor specifications. An interface map can be either predefined or custom. A predefined interface map is one that ships with Apstra software and supports most qualified Juniper devices. A custom interface map is one that is created by the user to meet specific requirements. An interface map can be stored in either the global catalog or the blueprint catalog. The global catalog contains all the interface maps that are available for use in any blueprint. The blueprint catalog contains the interface maps that are imported from the global catalog and used in a specific blueprint.

When a member of your organization makes changes to a predefined interface map, the following statements are correct:

Changes to interface maps in the global catalog do not affect interface maps that have already been imported into blueprint catalogs. This means that the existing blueprints that use the original version of the interface map will not be impacted by the changes. However, if you want to use the updated version of the interface map in a new or existing blueprint, you need to import it again from the global catalog.

Any changes made to predefined interface maps are discarded when Apstra is upgraded. This means that the changes will not be preserved across different versions of Apstra software. If you want to retain a customized interface map through Apstra upgrades, you need to clone the predefined interface map, give it a unique name, and customize it instead of changing the predefined one directly.

Therefore, the correct answer is A and B. Changes to interface maps in the global catalog do not affect interface maps that have already been imported into blueprint catalogs and any changes made to predefined interface maps are discarded when Apstra is upgraded. References: Edit Interface Map | Apstra 4.2 | Juniper Networks

According to the Juniper documentation1, a template is a configuration template that defines a network’s policy intent and structure. A template can be either rack-based or pod-based, depending on the type and number of racks and pods in the network design. A template includes the following details:

Policies: These are the parameters that apply to the entire network, such as the overlay control protocol, the ASN allocation scheme, and the underlay type.

Structure: This is the physical layout of the network, such as the type and number of racks, pods, spines, and leaves. The structure also defines the leaf-to-spine interconnection, which is the number and type of links between the leaf and spine devices. The leaf-to-spine interconnection can be either single or dual, depending on the redundancy and bandwidth requirements.

Therefore, the correct answer is A. the leaf-to-spine interconnection. This is a component that is defined in a template, as it determines the physical connectivity of the network. The speed of the links, the number of spine devices, and the definition of IP pools are not components that are defined in a template, as they are either derived from the device profiles, the resource pools, or the blueprint settings. References: Templates Introduction | Apstra 4.2 | Juniper Networks

To create a new routing zone, you must specify the VRF Name, VLAN ID, and VNI for the routing zone. These are the mandatory fields in the user interface shown in the exhibit. The VRF Name is the name of the L3 domain that isolates the IP traffic of the routing zone from other routing zones. The VLAN ID is the identifier for the VLAN tagged Layer 3 links on external connections. The VNI is the VxLAN Network Identifier associated with the routing zone. The Routing Policies are optional fields that allow you to configure import and export route targets for the routing zone. These are onlyapplicable for EVPN routing zones, which use MP-EBGP as the overlay control protocol. The other options are incorrect because:

A. VRF Name only is wrong because you also need to specify the VLAN ID and VNI for the routing zone.

B. VRF Name and Routing policies is wrong because you also need to specify the VLAN ID and VNI for the routing zone. Routing policies are optional and only relevant for EVPN routing zones.

D. VRF Name, VLAN ID, VNI, Routing Policies is wrong because Routing Policies are optional and not required to create a new routing zone. References:

Routing Zones (Virtual)

Data Center Automation Using Juniper Apstra

Device profiles are objects that associate a specific vendor model to a logical device in Juniper Apstra. Device profiles contain extensive hardware model details, such as form factor, ASIC, CPU, RAM, ECMP limit, and supported features. Device profiles also define how configuration is generated, how telemetry commands are rendered, and how configuration is deployed on a device. Device profiles enable the Apstra system to render and deploy the configuration according to the Apstra Reference Design12. References:

Device Profiles

Juniper Device Profiles

In the case of IP Clos data center five-stage fabric design, the super spines are the devices that provide the highest level of aggregation in the network. They have two main roles:

Super spines are used to interconnect two different data center pods. A pod is a cluster of leaf and spine devices that form a 3-stage Clos topology. A 5-stage Clos topology consists of multiple pods that are connected by the super spines. This allows for scaling the network to support more devices and bandwidth.

Super spines connect to all spine devices within the five-stage architecture. The spine devices are the devices that provide the second level of aggregation in the network. They connect to the leaf devices, which are the devices that provide access to the end hosts. The super spines connect to all the spine devices in the network, regardless of which pod they belong to. This provides any-to-any connectivity between the pods and enables optimal routing and load balancing.

The following two statements are incorrect in this scenario:

Super spines are used to connect leaf nodes within a data center pod. This is not true, because the leaf nodes are connected to the spine nodes within the samepod. The super spines do not connect to the leaf nodes directly, but only through the spine nodes.

Super spines are always connected to an external data center gateway. This is not true, because the super spines are not necessarily involved in the external connectivity of the data center. The external data center gateway is a device that provides the connection to the outside network, such as the Internet or another data center. The external data center gateway can be connected to the super spines, the spine nodes, or the leaf nodes, depending on the design and the requirements of the network.

References:

5-stage Clos Architecture — Apstra 3.3.0 documentation

5-Stage Clos Architecture | Juniper Networks

Extreme Fabric Automation Administration Guide

Juniper Apstra supports three deploy modes for devices: Deploy, Drain, and Ready. These modes determine the configuration and state of the devices in the data center fabric12.

Deploy: This mode applies the full Apstra-rendered configuration to the device, according to the Apstra Reference Design. The device state becomes IS-ACTIVE and the device is ready to carry traffic in the fabric12.

Drain: This mode adds a “drain” configuration to the device, which prevents any new traffic from entering the device. The device state becomes IS-READY and the device is prepared for maintenance or decommissioning12.

Ready: This mode removes the Apstra-rendered configuration from the device, leaving only the basic configuration such as device hostname, interface descriptions, and port speed/breakout. The device state becomes IS-READY and the device is not part of the fabric12. References:

Device Configuration Lifecycle

Set Deploy Mode (Datacenter)

The Juniper Apstra Rendered configuration is the configuration that is generated from the staged blueprint and applied to the devices in the network. The Rendered configuration is dynamically rendered at commit time, which means that it is created on the fly based on the latest changes and validations in the blueprint. The Rendered configuration is not stored in any database, but it can be viewed in the Apstra UI or downloaded as a file. The Rendered configuration reflects the desired state of the network as defined by the intent of the blueprint. The other options are incorrect because:

A. It is built at commit time and stored in a MySQL database is wrong because the Rendered configuration is not stored in any database, let alone a MySQLdatabase. Apstra uses a graph database to store the network topology and configuration data, not a relational database like MySQL.

B. It is stored in a NoSQL database and incrementally updated is wrong because the Rendered configuration is not stored in any database, let alone a NoSQL database. Apstra uses a graph database to store the network topology and configuration data, not a non-relational database like NoSQL. The Rendered configuration is not incrementally updated, but dynamically rendered at commit time.

D. It is rendered from the graph database and stored locally is wrong because the Rendered configuration is not rendered from the graph database, but from the staged blueprint. The graph database stores the network topology and configuration data, but the Rendered configuration is generated from the blueprint, which is a logical representation of the network design and intent. The Rendered configuration is not stored locally, but it can be downloaded as a file if needed. References:

Config Rendering in Juniper Apstra

AOS Device Configuration Lifecycle

Configlets (Datacenter Design)

In the EVPN-VXLAN data center fabric bridged overlay architecture shown in the exhibit, the servers are connected to Leaf1 and Leaf6 using the same virtual network identifier (VNI). This means that the servers belong to the same Layer 2 domain and can communicate with each other using VXLAN tunnels across the fabric. The underlay network provides the IP connectivity between the leaf and spine devices, and it uses EBGP as the routing protocol. Therefore, the following two statements are correct in this scenario:

Loopback IPv4 addresses must be advertised into the EBGP underlay from leaf and spine devices. This is because the loopback addresses are used as the source and destination IP addresses for the VXLAN tunnels, and they must be reachable by all the devices in the fabric. The loopback addresses are also used as the router IDs and the BGP peer addresses for the EBGP sessions.

The underlay EBGP peering’s must be established between leaf and spine devices. This is because the EBGP sessions are used to exchange the underlay routing information and the EVPN routes for the overlay network. The EBGPsessions are established using the loopback addresses of the devices, and they follow a spine-and-leaf topology, where each leaf device peers with all the spine devices, and each spine device peers with all the leaf devices.

The following two statements are incorrect in this scenario:

The underlay must use IRB interfaces. This is not true, because the underlay network does not provide any Layer 3 gateway functionality for the overlay network. The IRB interfaces are used to provide inter-VXLAN routing within the fabric, which is not the case in the bridged overlay architecture. The IRB interfaces are used in the edge-routed bridging (ERB) or the centrally-routed bridging (CRB) architectures, which are different from the bridged overlay architecture.

The underlay must be provisioned with PIMv2. This is not true, because the underlay network does not use multicast for the VXLAN tunnels. The VXLAN tunnels are established using EVPN, which uses BGP to distribute the MAC and IP addresses of the end hosts and the VTEP information of the devices. EVPN eliminates the need for multicast in the underlay network, and it provides optimal forwarding and fast convergence for the overlay network.

References:

Exploring EVPN-VXLAN Overlay Architectures – Bridged Overlay

EVPN LAGs in EVPN-VXLAN Reference Architectures

EVPN-VXLAN Configuration Guide

To configure a static route for traffic to exit a configured routing zone, you need to use the Connectivity Templates feature in the Juniper Apstra UI. A Connectivity Template is a set of configuration parameters that can be applied to a device or a group of devices in a blueprint. You can use Connectivity Templates to configure static routes, BGP, OSPF, and other network services. To create a Connectivity Template, you need to go to the Staged tab and select Connectivity Templates from the left menu. Then, you can click on the + icon to create a new template. You can specify the name, description, andscope of the template. The scope determines which devices or device groups the template will be applied to. You can also specify the order of the template, which determines the priority of the template when multiple templates are applied to the same device. After creating the template, you can add configuration items to the template. To add a static route, you need to select Static Route from the drop-down menu and enter the destination network, subnet mask, and next-hop IP address. You can also specify the administrative distance and the track object for the static route. After adding the configuration items, you need to save the template and commit the changes to the blueprint. The other options are incorrect because:

A. under Active -> Virtual -> Routing Zones is wrong because this option allows you to view and modify the existing routing zones, but not to configure static routes for them.

B. under Staged -> Virtual -> Routing Zones is wrong because this option allows you to create and delete routing zones, but not to configure static routes for them.

C. under Active -> Connectivity Templates is wrong because this option allows you to view the existing connectivity templates, but not to create or modify them. References:

Connectivity Templates

Data Center Automation Using Juniper Apstra