Juniper JN0-480 - Data Center Specialist (JNCIS-DC)

 Probes are the basic unit of abstraction in Intent-Based Analytics (IBA). They are used to collect, process, and analyze data from the network and raise anomalies based on specified conditions. Probes are composed of processors and stages that form a directed acyclic graph (DAG) of data flow. The following statements are correct about probes:

A. Default probes can be cloned, modified, and saved. This is true because Apstra provides a set of default probes that cover common use cases and scenarios. These probes can be cloned and modified to suit the specific needs of the user. The modified probes can be saved as new probes with different names and descriptions. This allows the user to customize and extend the functionality of the default probes.

D. Default probes are enabled, based on the intent for a blueprint. This is true because Apstra enables or disables the default probes automatically based on the intent of the blueprint. The intent of the blueprint is the high-level description of the desired state and behavior of the network. Apstra uses the intent to determine which default probes are relevant and applicable for the blueprint and enables them accordingly. For example, if the intent of the blueprint is to deployan EVPN-VXLAN fabric, Apstra will enable the default probes related to EVPN-VXLAN, such as EVPN-VXLAN Anomaly Detection, EVPN-VXLAN Fabric Health, and EVPN-VXLAN Fabric Validation. The following statements are incorrect about probes:

B. Only the variable parameters for default probes can be edited and saved. This is false because the user can edit and save any parameters for the default probes, not just the variable ones. The variable parameters are the ones that depend on the network topology, devices, or configuration, such as device names, interface names, IP addresses, VLAN IDs, etc. The user can also edit and save the fixed parameters, such as the duration, threshold, condition, etc. However, the user cannot edit and save the default probes directly. The user must clone the default probes first and then edit and save the cloned probes as new probes.

C. All default probes are enabled for all blueprints. This is false because Apstra does not enable all default probes for all blueprints. Apstra enables the default probes based on the intent of the blueprint, as explained above. This means that only the default probes that are relevant and applicable for the blueprint are enabled. For example, if the intent of the blueprint is to deploy a BGP IP fabric, Apstra will not enable the default probes related to EVPN-VXLAN, since they are not relevant for the blueprint. The user can also manually enable or disable the default probes as needed. References:

Probes

Create Probe

Intent-Based Analytics Overview

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

According to the Juniper documentation1, a routing zone is an L3 domain, the unit of tenancy in multi-tenant networks. You create routing zones for tenants to isolate their IP traffic from one another, thus enabling tenants to re-use IP subnets. In addition to being in its own VRF, each routing zone can be assigned its own DHCP relay server and external system connections. You can create one or more virtual networks within a routing zone, which means a tenant can stretch its L2 applications across multiple racks within its routing zone. For virtual networks with Layer 3 SVI, the SVI is associated with a Virtual Routing and Forwarding (VRF) instance for each routing zone isolating the virtual network SVI from other virtual network SVIs in other routing zones. Therefore, the correct answer is D. A routing zone is used to enable the communication between two VNIs within a VRF. A routing zone is not used for L4-L7 inspection, securing routing protocols, or requiring firewalls. Those are not the purposes of a routing zone in Juniper Apstra software. References: Routing Zones

Referring to the exhibit, the image shows a user interface of the Juniper Apstra software application, which is used for network management and configuration. The image shows the Virtual Networks table under the Resources menu, which displays the details of the VLANs and VXLANs in the network. The table has 11 columns, but only 9 are visible in the image. The other two columns are IPv6 Connectivity and IPv6 Subnet, which are hidden by default. To display the IPv6 subnets for all of the listed VXLANs, the user needs to select Columns, then select IPv6 Subnet. This will show the IPv6 Subnet column in the table, which will display the IPv6 addresses assigned to the VXLANs from the IPv6 pools. For more information, see Virtual Networks (Resources). References:

Virtual Networks (Resources)

IPv6 Pools (Resources)

Apstra User Guide

To make the IP fabric a valid IP fabric, the connection between the two spine nodes must be removed. This is because an IP fabric is a network topology that uses a spine-leaf architecture, where the spine devices are only connected to the leaf devices, and the leaf devices are only connected to the spine devices. This creates a non-blocking, high-performance, and scalable network that supports Layer 3 routing protocols such as BGP or OSPF. The connection between the two spine nodes in the exhibit violates the spine-leaf design principle and introduces unnecessary complexity and potential loops in the network. The other options are incorrect because:

A. The IP fabric must consist of only one device model throughout the fabric is wrong because an IP fabric can support different device models as long as they are compatible and interoperable. The exhibit shows two different models of QFX switches, which are both supported by Juniper Networks for IP fabric deployments.

B. The connection between the two spine nodes must be increased to 40 Gbps is wrong because increasing the speed of the connection does not make the IP fabric valid. The connection between the two spine nodes should be removed, as explained above.

C. The IP fabric connections must be increased to a speed greater than 10 Gbps is wrong because the speed of the connections does not affect the validity of theIP fabric. The IP fabric can use any speed that meets the bandwidth and performance requirements of the network. 10 Gbps is a common speed for IP fabric connections, but higher or lower speeds can also be used depending on the network design and devices. References:

IP Fabric Underlay Network Design and Implementation

IP Fabric Overview

IP Fabric: Automated Network Assurance Platform

According to the Juniper documentation1, the Resources menu in the Juniper Apstra UI allows you to create and manage various types of resources that are assigned to different elements of the network. Resources include the following types:

IPv4 (including Host IPv4)

IPv6 (including Host IPv6)

ASN (autonomous system number)

VNI (virtual network identifier)

VLAN (virtual local area network)

Integer (used for pool type VLAN in local pools in Freeform blueprints)

Therefore, the correct answer is C and D. ASN pools and IP pools are two types of resources that can be created in the Resources menu. Bridge domain identifier (BDI) and DHCP pools are not applicable in this scenario, because they are not part of the resources types supported by Juniper Apstra. References: Resources Introduction | Apstra 4.1 | 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

According to the Juniper documentation1, a predefined device profile is a configuration template that is shipped with Apstra software and supports most qualified Juniper devices. A predefined device profile cannot be changed, since any changes would be discarded and overwritten when you upgrade the Apstra server version. If you want to customize a predefined device profile, you can clone and edit it instead. Therefore, the correct answer is A. The changes you make to a predefined device profile will be discarded and overwritten when upgrading the Apstra server version. References: Edit Device Profile | Apstra 4.2 | Juniper Networks

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)