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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)

Referring to the exhibit, the image shows a simplified diagram of an IP fabric network connecting two servers, labeled as Server A and Server B. The IP fabric is a network architecture that uses a Clos topology to provide high bandwidth, low latency, and scalability for data center networks. The IP fabric consists of spine and leaf devices that use BGP as the routing protocol and VXLAN as the overlay technology1.

A broadcast domain is a logical portion of a network where any device can directly transmit broadcast frames to other devices at the data link layer (OSI Layer 2). A broadcast frame is a frame that has a destination MAC address of all ones (FF:FF:FF:FF:FF:FF), which means that it is intended for all devices in the same broadcast domain. A broadcast domain is usually bounded by a router, which does not forward broadcast frames to other networks2.

In the exhibit, there are two broadcast domains that an Ethernet frame will pass through when traversing the IP fabric from Server A to Server B. The first broadcast domain is the one that contains Server A and the leaf device that it is connected to. The second broadcast domain is the one that contains Server B and the leaf device that it is connected to. The IP fabric itself is not a broadcast domain, because it uses IP routing and VXLAN encapsulation to transport the Ethernet frames over the Layer 3 network. Therefore, the statement C is correct in this scenario.

The following three statements are incorrect in this scenario:

A. 1. This is not true, because there are not one, but two broadcast domains that an Ethernet frame will pass through when traversing the IP fabric from Server A to Server B. The IP fabric itself is not a broadcast domain, because it uses IP routing and VXLAN encapsulation to transport the Ethernet frames over the Layer 3 network.

B. 4. This is not true, because there are not four, but two broadcast domains that an Ethernet frame will pass through when traversing the IP fabric from Server A to Server B. The spine devices and the leaf devices that are not connected to the servers are not part of the broadcast domains, because they use IP routing and VXLAN encapsulation to transport the Ethernet frames over the Layer 3 network.

D. 3. This is not true, because there are not three, but two broadcast domains that an Ethernet frame will pass through when traversing the IP fabric from Server A to Server B. The IP fabric itself is not a broadcast domain, because it uses IP routing and VXLAN encapsulation to transport the Ethernet frames over the Layer 3 network.

References:

IP Fabric Overview

Broadcast Domain - NetworkLessons.com

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 toacknowledge the device, which changes its state to Out of Service Ready (OOS-READY)12. References:

Managing Devices

AOS Device Configuration Lifecycle

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)

VMware anomaly detection is a feature of Apstra that provides visibility and validation of the virtual network settings and the physical network settings in a VMware vSphere environment. To enable this feature, Apstra requires a connection to a vCenter server that manages the ESX/ESXi hosts and the VMs connected to the Apstra-managed leaf switches. The vCenter server must be configured under External Systems in the Apstra web interface, and the vCenter integration must be staged and committed in the blueprint. This allows Apstra to collect information about VMs, ESX/ESXi hosts, port groups, and VDS, and to flag any inconsistencies or mismatches that might affect VM connectivity. The other options are incorrect because:

VMware anomaly detection is not on by default. It must be enabled by configuring a vCenter server under External Systems and adding a virtual infra to the blueprint.

VMware anomaly detection does not require a VMware hypervisor with exports enabled. It only requires LLDP transmit to be enabled on the VMware distributed virtual switch to associate host interfaces with leaf interfaces.

VMware anomaly detection does not require an Apstra server running on VMware. It can run on any supported platform, such as Linux, Windows, or Docker. References:

VMware vCenter/vSphere Virtual Infra

Anomalies (Service)

A Better Experience: VMware + 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. Therefore, the correct answer is D. routing zone. A routing zone is the construct within which you create virtual networks to achieve multitenancy for applications. References: Routing Zones

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

A security policy is the feature that would be used to accomplish the task of controlling access to other virtual networks in the same routing zone using the Juniper Apstra UI. A security policy allows you to define rules that specify which traffic is allowed or denied between different virtual networks, IP endpoints, or routing zones. A security policy can be applied to one or more virtual networks in the same routing zone, and it can use various criteria to match the traffic, such as source and destination IP addresses, protocols, ports, or tags. A security policy can also support DHCP relay, which enables the forwarding of DHCP requests from one virtual network to another. The other options are incorrect because:

A. interface policy is wrong because an interface policy is a feature that allows you to configure the interface parameters for the devices in a blueprint, such as interface names, speeds, types, or descriptions. An interface policy does not affect the access control between different virtual networks in the same routing zone.

B. anti-affinity policy is wrong because an anti-affinity policy is a feature that allows you to prevent certain devices or logical devices from being placed in thesame rack or leaf pair in a blueprint. An anti-affinity policy is used to enhance the availability and redundancy of the network, not to control the access between different virtual networks in the same routing zone.

C. routing policy is wrong because a routing policy is a feature that allows you to configure the routing parameters for the devices in a blueprint, such as routing protocols, autonomous system numbers, route filters, or route maps. A routing policy does not affect the access control between different virtual networks in the same routing zone, unless the routing policy is used to filter or modify the routes exchanged between different routing zones. References:

Security Policy

Interface Policy

Anti-Affinity Policy

Routing Policy

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

The graph query output shown in the exhibit is a JSON representation of an interface node and its properties in the Apstra graph database. Based on the output, we can infer the following statements:

The output shows a LAG connection. This is true because the interface node has a property called lag_mode which is set to lacp_active, indicating that the interface is part of a link aggregation group (LAG) that uses the Link Aggregation Control Protocol (LACP) to negotiate the link state and parameters12.

The switch in the output is a Juniper device. This is true because the interface node has a property called if_name which is set to ae2, indicating that the interface name follows the Juniper naming convention for aggregated Ethernet interfaces34.

The interface has an IP address assigned to it. This is false because the interface node has properties called ipv4_addr and ipv6_addr which are both set to null, indicating that the interface does not have any IPv4 or IPv6 address configured2.

The interface has tags assigned to it. This is false because the interface node has a property called tags which is set to null, indicating that the interface does not have any tags associated with it2. References:

Link Aggregation Overview

Processor: Generic Graph Collector

Understanding Aggregated Ethernet Interfaces and LACP

Graph