JN0-480 Data Center Specialist (JNCIS-DC) Questions and Answers

 In Juniper Apstra, a widget is a graphical element that displays data from an intent-based analytics (IBA) probe. A widget can be used to monitor different aspects of the network and raise alerts to any anomalies. A widget can be viewed by itself or added to an analytics dashboard. A dashboard is a collection of widgets that can be customized and organized according to the user’s preference1.

The main dashboard in Juniper Apstra is the blueprint dashboard, which is the default view that shows the network information and configuration for the active blueprint. A blueprint is a logical representation of the network design and intent. The blueprint dashboard can display the system-generated dashboards, the user-generated dashboards, and the individual widgets that are relevant to the network2.

To make a widget appear on the main dashboard in Juniper Apstra, the user needs to set the Default toggle switch to On for the desired widget. This will add the widget to the blueprint dashboard, where it can be viewed along with other network information. The user can also remove the widget from the blueprint dashboard by setting the Default toggle switch to Off for the widget3. Therefore, the statement D is correct in this scenario.

The following three statements are incorrect in this scenario:

• When creating the widget, select the Add to Blueprint Dashboard option. This is not true, because there is no such option when creating a widget in Juniper Apstra. The user can only select the widget type, the probe, and the display mode when creating a widget4. To add the widget to the blueprint dashboard, the user needs to set the Default toggle switch to On for the widget after creating it3.
• On the blueprint dashboard, click on the Add Widget option. This is not true, because there is no such option on the blueprint dashboard in Juniper Apstra. The user can only view, edit, or delete the existing widgets and dashboards on the blueprint dashboard2. To add a widget to the blueprint dashboard, the user needs to set the Default toggle switch to On for the widget from the widgets table view3.
• Widgets automatically appear on the blueprint dashboard. This is not true, because widgets do not automatically appear on the blueprint dashboard in Juniper Apstra. The user needs to manually add the widgets to the blueprint dashboard by setting the Default toggle switch to On for the widgets that they want to see on the blueprint dashboard3. The only exception is the widgets that are part of the system-generated dashboards, which are automatically created and added to the blueprint dashboard based on the state of the active blueprint2.

References:

• Widgets Overview
• Blueprint Summaries and Dashboard
• Widgets Introduction
• Create Widget

The cable map is a graphical representation of the physical connections between the devices in the data center fabric. It shows the status of the cables, interfaces, and BGP sessions for each device. You can use the cable map to identify and troubleshoot any cable, interface, or BGP anomalies that may occur in the fabric. You can also filter the cable map by device name, device type, device role, device state, cable state, interface state, or BGP state12. References:

• Cable Map Overview
• Cable Map User Guide

According to the Juniper documentation1, a five-stage Clos architecture allows for large-scale topologies with an additional aggregation layer that interconnects multiple pods into a single fabric. A pod is a group of racks that share the same spine devices. A rack is a group of leaf devices that connect to the same servers. To create a five-stage Clos network using Juniper Apstra, you need to choose the pod-based fabric type in the template creation wizard. This will allow you to specify the number of pods, planes, spines, and leaves for your network design. Therefore, the correct answer is D. pod-based. References: 5-Stage Clos Architecture | Apstra 4.1 | Juniper Networks

Intent-based analytics (IBA) is a feature of Juniper Apstra that allows you to combine intent from the network design with current and historic data from devices to reason about the network at-large1. IBA has the following characteristics:

• It is a real-time information processing pipeline. This means that IBA can ingest, process, and analyze large amounts of data from devices in real time, using agents and probes. Agents are software components that collect data from devices and send them to the Apstra server. Probes are user-defined queries that aggregate data across devices and generate advanced data that can be more easily reasoned about1.
• It is used to establish network performance baselines. This means that IBA can use the advanced data to measure and monitor the network performance against the expected outcomes and service levels. IBA can also use the historic data to create baselines that represent the normal behavior and state of the network2.
• It alerts the network operator when network performance moves away from the baseline. This means that IBA can detect and report any anomalies or deviations from the baseline or the intent in the network. IBA can also provide insights and recommendations for troubleshooting and resolving the issues2.

The following two statements are incorrect in this scenario:

• It indicates when device operating versions require updating. This is not true, because IBA does not provide any information or guidance about the device operating versions or updates. IBA is focused on the network performance and compliance, not on the device maintenance or upgrade1.
• It collects information from vendor websites. This is not true, because IBA does not collect any information from vendor websites or external sources. IBA only collects information from the devices in the network, using agents and probes1.

References:

• Intent-Based Analytics — Apstra 3.3.0 documentation
• What is Intent Based Networking? | Juniper Networks US

Time Voyager is a feature of Juniper Apstra that allows you to restore previous revisions of a blueprint, which is a logical representation of your network design and configuration. Time Voyager automatically saves the five most recent blueprint commits, which are the changes that you apply to the network. You can also manually save up to twenty-five revisions by keeping them, which prevents them from being overwritten by new commits. Therefore, the correct answer is B and D. Time Voyager retains the five most recent blueprint commits and Time Voyager retains up to twenty-five saved revisions. References: Time Voyager | Apstra 4.1 | Juniper Networks, Time Voyager Introduction | Apstra 4.2 | Juniper Networks, Juniper Apstra at a Glance | Flyer

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

According to the Juniper documentation1, a VXLAN virtual network is a collection of Layer 2 forwarding domains that span multiple racks in a fabric. A VXLAN virtual network requires a name and a VXLAN network identifier (VNI), which is a 24-bit number that identifies the virtual network. The VNI can be either explicitly assigned or auto-assigned from a resource pool. A VXLAN virtual network can also have Layer 3 connectivity, which enables routing between different VNIs within a routing zone. A routing zone is an L3 domain that isolates the IP traffic of different tenants. A routing zone can have one or more VNIs associated with it. To enable Layer 3 connectivity, a VXLAN virtual network needs an IP subnet, which is a range of IP addresses that can be assigned to the hosts in the virtual network. The IP subnet can be either explicitly assigned or auto-assigned from a resource pool. Therefore, the correct answer is A and C. IP subnet and VXLAN VNI are two components that would be automatically derived when enabling a new VXLAN virtual network using Juniper Apstra. References: Virtual Networks | Apstra 4.1 | Juniper Networks

A Juniper Apstra rack is a physical entity that contains one or more network devices, such as leaf nodes, access switches, or generic systems. A rack is used to organize and manage the network devices in the Apstra software application. A rack has the following characteristics:

• It stores information on how leaf nodes connect to generic devices. This is because a rack can include generic systems, which are devices that are not managed by Juniper Apstra, but are connected to the network. A generic system can be a server, a firewall, a load balancer, or any other device that has a networkinterface. A rack stores the information on how the leaf nodes, which are the devices that provide access to the end hosts, connect to the generic devices, such as the port number, the link speed, the LAG mode, and the roles1.
• It has a rack type, which defines the type and number of leaf devices, access switches, and/or generic systems that are used in the rack. A rack type is a resource that is created in the data center design phase, and it does not specify the vendor or the model of the devices. A rack type can be predefined or custom-made, and it can be used to create multiple racks with the same structure and configuration2.
• It has a rack build, which assigns the specific vendor and model of the devices to the rack. A rack build is created in the staged phase, and it uses the rack type as a template. A rack build can also assign the resources, such as the IP addresses, the ASNs, and the VNIs, to the devices in the rack3.
• It has a rack deployment, which applies the network configuration and services to the devices in the rack. A rack deployment is performed in the active phase, and it uses the rack build as a reference. A rack deployment can also monitor the network performance and compliance of the devices in the rack4.

The following three statements are incorrect in this scenario:

• It stores information on how pods connect to super spines. This is not true, because a rack does not store any information on the pod or the super spine level of the network. A pod is a cluster of leaf and spine devices that form a 3-stage Clos topology, and a super spine is a device that connects multiple pods in a 5-stage Clos topology. A rack only stores information on the leaf and the access level of the network1.
• It stores IP address and ASN pool information. This is not true, because a rack does not store any information on the IP address and ASN pools. IP address and ASN pools are resources that are created in the data center design phase, and they contain a range of IP addresses and ASNs that can be assigned to the devices and the virtual networks. A rack only uses the IP address and ASN pools to assign the resources to the devices in the rack build2.
• It stores device port data rates and vendor information. This is not true, because a rack does not store any information on the device port data rates and vendor information. The device port data rates and vendor information are specified in the rack build, which assigns the specific vendor and model of the devices to the rack. A rack only uses the rack build to apply the network configuration and services to the devices in the rack deployment3.

References:

• Racks (Staged)
• Rack Types (Datacenter Design)
• Rack Builds (Staged)
• Racks (Active)

Juniper Apstra role-based access control (RBAC) is a feature that allows you to specify access permissions for different users based on their roles. RBAC servers are remote network servers that authenticate and authorize network access based on roles assigned to individual users within an enterprise1. Juniper Apstra has four predefined user roles: administrator, device_ztp, user, and viewer2. The administrator role is the most powerful role, and it can see all permissions and perform all actions in the Apstra software application. The administrator role can also create, clone, edit, and delete user roles, except for the four predefined user roles, which cannot be modified2. Therefore, the statement that the administrator role can see all permissions is correct.

The following three statements are incorrect in this scenario:

• The viewer role is predefined and can be deleted. This is not true, because the viewer role is one of the four predefined user roles, and it cannot be deleted. The viewer role is the most restricted role, and it can only view the network information and configuration, but not make any changes2.
• The user role can create roles. This is not true, because the user role is one of the four predefined user roles, and it cannot create roles. The user role can perform most of the network configuration and management tasks, but it cannot access the platform settings or the user management features2.
• The administrator role is the only predefined role. This is not true, because there are four predefined user roles, not just one. The other three predefined user roles are device_ztp, user, and viewer2.

References:

• Providers — Apstra 3.3.0 documentation
• User/Role Management (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

When an agent installation is successful, devices are placed into the Out of Service Quarantined (OOS-QUARANTINED) state using the Juniper Apstra UI. This state means that the device is not yet managed by Apstra and has not been assigned to any blueprint. The device configuration at this point is called Pristine Config. To make the device ready for use in a blueprint, you need to acknowledge the device, which is a manual action that confirms the device identity and ownership. Acknowledging the device changes its status to Out of Service Ready (OOS-READY)12. References:

• Managing Devices
• AOS Device Configuration Lifecycle

Device A serves as a spine in an IP fabric. An IP fabric is a network architecture that uses a spine-leaf topology to provide high performance, scalability, and reliability for data center networks. A spine-leaf topology consists of two layers of devices: spine devices and leaf devices. Spine devices are the core devices that interconnect all the leaf devices using equal-cost multipath (ECMP) routing. Leaf devices are the edge devices that connect to the servers, storage, or other network devices. In the exhibit, Device A is connected to four leaf devices using multiple links, which indicates that it is a spine device. The other options are incorrect because:

• A. leaf is wrong because a leaf device is an edge device that connects to the servers, storage, or other network devices. In the exhibit, Device A is not connected to any servers, storage, or other network devices, but only to four leaf devices, which indicates that it is not a leaf device.
• C. super spine is wrong because a super spine device is a higher-level device that interconnects multiple spine devices in a large-scale IP fabric. A super spine device is typically used when the number of leaf devices exceeds the port density of a single spine device. In the exhibit, Device A is not connected to any other spine devices, but only to four leaf devices, which indicates that it is not a super spine device.
• D. server is wrong because a server device is a compute or storage device that connects to a leaf device in an IP fabric. A server device is typically the end host that provides or consumes data in the network. In the exhibit, Device A is not connected to any leaf devices, but only to four leaf devices, which indicates that it is not a server device. References:
• IP Fabric Underlay Network Design and Implementation
• IP Fabric Overview
• IP Fabric Architecture

Juniper Apstra provides four system-defined user roles that are available in the Apstra GUI environment. They are: administrator, device_ztp, viewer, and user1. Based on the web search results, we can infer the following statements:

• viewer: This role includes permissions to only view various elements in the Apstra system, such as blueprints, devices, design, resources, external systems, platform, and others. Users with this role cannot create, edit, or delete any element12.
• user: This role includes permissions to view and edit various elements in the Apstra system, such as blueprints, devices, design, resources, external systems, platform, and others. Users with this role cannot create or delete any element12.
• authorized: This is not a system-defined user role in Juniper Apstra. It is a term used to describe users who have been authenticated by an external system, such as LDAP, Active Directory, TACACS+, or RADIUS3.
• root: This is not a system-defined user role in Juniper Apstra. It is a term used to describe the superuser account on a Linux system, which has full access to all commands and files. Creating a user in the Apstra GUI does not provide that user access to the Apstra platform via SSH. To access the Apstra platform via SSH, you must create a local Linux system user4. References:
• User / Role Management Introduction
• User/Role Management (Platform)
• AAA Providers
• User Profile Management

 In Juniper Apstra, a blueprint is a logical representation of the network design and configuration. When you create a new blueprint, you need to commit the changes to apply them to the network devices. However, committing the changes does not mean that the network is immediately updated and operational. It may take some time for the network to converge and reflect the new state of the blueprint. During this time, you may see some anomalies related to BGP in the main dashboard, which indicate that the BGP sessions are not established or stable between the devices. These anomalies are usually temporary and will disappear once the network converges and the BGP sessions are up and running. Therefore, the statement B is the most likely cause of these anomalies in this scenario.

The following three statements are less likely causes of these anomalies in this scenario:

• You have misconfigured ASNs. This is possible, but not very likely, because Juniper Apstra provides ASN pools that can be automatically assigned to the devices based on their roles. You can also manually specify the ASNs for the devices, but you need to ensure that they are unique and consistent with the network design. If you have misconfigured ASNs, you may see some anomalies related to BGP, but they will not disappear after the network converges. You will need to fix the ASNs and commit the changes again to resolve the anomalies.
• Spine-leaf links are incorrectly set. This is possible, but not very likely, because Juniper Apstra provides connectivity templates that can be used to define the spine-leaf links based on the interface maps. You can also manually specify the spine-leaf links, but you need to ensure that they are correct and match the physical cabling. If you have incorrectly set the spine-leaf links, you may see some anomalies related to BGP, but they will not disappear after the network converges. You will need to fix the spine-leaf links and commit the changes again to resolve the anomalies.
• A generic system has not been configured. This is not relevant, because a generic system is a device that is not managed by Juniper Apstra, but is connected to the network. A generic system does not affect the BGP sessions between the devices that are managed by Juniper Apstra. If you have a generic system in your network, you need to configure it manually and ensure that it is compatible with the network design. A generic system does not cause any anomalies related to BGP in the main dashboard.

References:

• Blueprint Summaries and Dashboard
• BGP Session Flapping Probe
• Probe: BGP Session Monitoring

EVPN uses a route distinguisher (RD) value to identify which remote leaf device advertised the EVPN route. An RD is a 64-bit value that is prepended to the EVPN NLRI to create a unique VPNv4 or VPNv6 prefix. The RD value is usually derived from the IP address of the PE that originates the EVPN route. By comparing the RD values of different EVPN routes, a PE can determine which remote PE advertised the route and which VRF the route belongs to. The other options are incorrect because:

• B. a community tag is wrong because a community tag is an optional transitive BGP attribute that can be used to group destinations that share some common properties. A community tag does not identify the source of the EVPN route.
• C. a route target value is wrong because a route target (RT) value is an extended BGP community that is used to control the import and export of EVPN routes between VRFs. An RT value does not identify the source of the EVPN route.
• D. a VRF target value is wrong because there is no such thing as a VRF target value in EVPN. A VRF is a virtual routing and forwarding instance that isolates the IP traffic of different VPNs on a PE. A VRF does not have a target value associated with it. References:
• EVPN Fundamentals
• RFC 9136 - IP Prefix Advertisement in Ethernet VPN (EVPN)
• EVPN Type-5 Routes: IP Prefix Advertisement
• Understanding EVPN Pure Type 5 Routes

To keep virtual networks isolated from each other within the Juniper Apstra system, you can use one or more of the following methods:

• Enable Security Policy for virtual networks in the same Routing Zone. This allows you to define rules that control the traffic flow between different virtual networks within the same routing zone. You can specify the source and destination virtual networks, the protocol, the port, and the action (allow or deny) for each rule. The security policy is applied on the ingress interface of the leaf devices1.
• Use Connectivity Templates to block access within the same Routing Zone. This allows you to customize the connectivity between different racks within the same routing zone. You can create templates that define the link type, the routing protocol, and the access control list(ACL) for each rack pair. The ACL can be used to filter the traffic based on the source and destination IP addresses, the protocol, and the port2.
• Put each network in different Routing Zones. This allows you to create logical boundaries between different virtual networks based on the route target (RT) values. A routing zone is a collection of virtual networks that share the same RT for importing and exporting routes. Virtual networks in different routing zones do not exchange routes with each other, unless you configure remote EVPN gateways to connect them3. References:
• Security Policy
• Connectivity Templates
• Routing Zones