JN0-480 Exam Dumps - Juniper Certification Questions and Answers

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 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 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

A cabling anomaly is an issue that occurs when the physical connections between the devices in the data center fabric do not match the expected connections based on the Apstra Reference Design. A cabling anomaly can cause problems such as incorrect routing, suboptimal traffic flow, or device isolation. To remediate the issue, you can use one or both of the following methods:

• Manually edit the cabling map. This allows you to override the Apstra-generated cabling and specify the correct connections between the devices. You can use the Apstra UI or the Apstra CLI to edit the cabling map and apply the changes to the fabric12.
• Have Apstra autoremediate the cabling map using LLDP. This allows Apstra to collect LLDP data from the devices and use it to update the cabling map automatically. LLDP is a protocol that allows devices to exchange information about their identity, capabilities, and neighbors. Apstra can use the LLDP data to detect and correct any cabling errors in the fabric34. References:
• Edit Cabling Map (Datacenter)
• Import / Export Cabling Map (Datacenter)
• LLDP Overview
• Anomalies (Service)

To answer this question, we need to understand the concept of ESI values in EVPN LAGs. An ESI is a 10-byte value that identifies an Ethernet segment, which is a set of links that connect a multihomed device (such as a server) to one or more PE devices (such as leaf switches) in an EVPN network. The same ESI value must be configured on all the PE devices that connect to the same Ethernet segment. This allows the PE devices to form an EVPN LAG, which supports active-active or active-standby multihoming for the device. The ESI value can be manually configured (type 0) or automatically derived from LACP (type 1) or other methods. In the exhibit, Server A is connected to two leaf switches (QFX 5210) using a LAG with LACP enabled. Server B is connected to three leaf switches (QFX 5120) using a LAG with LACP enabled. Based on this information, the following statements are correct about ESI values for the server connections to the fabric:

• C. A valid ESI value for Server A is 0x00.10.10.10.10.10.10.10.10.10. This is true because this ESI value can be automatically derived from the LACP configuration on the QFX 5210 devices. The LACP system ID is usually based on the MAC address of the device, and the LACP administrative key is a 2-byte value that identifies the LAG. For example, if the MAC address of the QFX 5210 device is 00:10:10:10:10:10 and the LAG ID is 10, then the LACP system ID is 00:10:10:10:10:10 and the LACP administrative key is 00:0A. The ESI value is then derived by concatenating the LACP system ID and the LACP administrative key, resulting in 00:10:10:10:10:10:00:0A. This ESI value can be represented in hexadecimal notation as 0x00.10.10.10.10.10.00.0A, or padded with zeros as 0x00.10.10.10.10.10.00.0A.00.00. This ESI value must be configured on both QFX 5210 devices that connect to Server A.
• D. A valid ESI value for Server B is 0x00.00.00.00.00.00.00.00.00.00. This is true because this ESI value is a reserved value that indicates a single-homed device. Server B is connected to three leaf switches (QFX 5120) using a LAG, but it is not multihomed to any of them. This means that Server B does not need an ESI value to form an EVPN LAG with any of the leaf switches. Instead, Server B can use the reserved ESI value of 0x00.00.00.00.00.00.00.00.00.00, which indicates that it is a single-homed device and does not participate in any EVPN LAG. This ESI value must be configured on all three QFX 5120 devices that connect to Server B. Thefollowing statements are incorrect about ESI values for the server connections to the fabric:
• A. A valid ESI value for Server A is 0x00.00.00.00.00.00.00.00.00.00. This is false because this ESI value is a reserved value that indicates a single-homed device. Server A is connected to two leaf switches (QFX 5210) using a LAG with LACP enabled, which means that it is multihomed to both of them. This means that Server A needs an ESI value to form an EVPN LAG with the leaf switches. The ESI value must be unique and non-zero for each Ethernet segment, so the reserved ESI value of 0x00.00.00.00.00.00.00.00.00.00 is not valid for Server A.
• B. A valid ESI value for Server B is 0x00.20.20.20.20.20.20.20.20.20. This is false because this ESI value is not derived from the LACP configuration on the QFX 5120 devices. Server B is connected to three leaf switches (QFX 5120) using a LAG with LACP enabled, but it is not multihomed to any of them. This means that Server B does not need an ESI value to form an EVPN LAG with any of the leaf switches. Instead, Server B can use the reserved ESI value of 0x00.00.00.00.00.00.00.00.00.00, which indicates that it is a single-homed device and does not participate in any EVPN LAG. The ESI value of 0x00.20.20.20.20.20.20.20.20.20 is not valid for Server B, and it may cause conflicts with other Ethernet segments that use the same ESI value. References:
• Ethernet Segment Identifiers, ESI Types, and LACP in EVPN LAGs
• Understanding Automatically Generated ESIs in EVPN Networks
• Ethernet Segment in EVPN: All You Need to Know

The ztp.Json file on the Apstra ZTP server contains the configuration parameters for each device that is onboarded using ZTP. One of the parameters is the State, which can be one of the following values: init, ready, in_progress, done, error, or disabled. The State indicates the current status of the device in the ZTP process. For example, if the State is ready, it means that the device is ready to be onboarded by the Apstra ZTP server. If the State is done, it means that the device has completed the ZTP process and is managed by the Apstra server. The State can be manually set or changed in the ztp.Json file to control the behavior of the device during ZTP. For more information, see Apstra ZTP Configuration File. References:

• Apstra ZTP Configuration File
• Apstra ZTP Introduction
• Configure Apstra ZTP

BGP is the protocol used to advertise EVPN routes. EVPN routes are a new type of BGP network layer reachability information (NLRI) that carry MAC address and IP prefix information for Ethernet VPNs. EVPN routes are exchanged between PEs using BGP multiprotocol extensions (MP-BGP) over MPLS, VXLAN, SR, or SRv6 tunnels. EVPN routes enable PEs to learn the reachability of MAC addresses and IP prefixes of different sites within the same EVPN instance. EVPN routes also support various features such as fast convergence, redundancy, aliasing, and inter-subnet routing. The other options are incorrect because:

• A. OSPF is wrong because OSPF is an interior gateway protocol (IGP) that is used to advertise IP routes within an autonomous system. OSPF is not used to advertise EVPN routes, which are a type of BGP NLRI that carry MAC address and IP prefix information for Ethernet VPNs.
• C. IS-IS is wrong because IS-IS is an interior gateway protocol (IGP) that is used to advertise IP routes and MPLS labels within an autonomous system. IS-IS is not used to advertise EVPN routes, which are a type of BGP NLRI that carry MAC address and IP prefix information for Ethernet VPNs.
• D. RIP is wrong because RIP is an interior gateway protocol (IGP) that is used to advertise IP routes within an autonomous system. RIP is not used to advertise EVPN routes, which are a type of BGP NLRI that carry MAC address and IP prefix information for Ethernet VPNs. 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

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. If you’re using multiple routing zones, external system connections must be from leaf switches in the fabric. Routing between routing zones must be accomplished with external systems. Therefore, the correct answer is D. Use interconnection through an external gateway. References: Routing Zones

The deploy phase is the final step in the Juniper Apstra data center fabric design and deployment process. In this phase, you apply the Apstra-rendered configuration to the devices and verify the intent of the blueprint. Based on the web search results, we can infer the following actions are required during the deploy phase12:

• Assign device profiles to the blueprint. This action associates a specific vendor model to each logical device in the blueprint. 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 Design34.
• Assign resources to the blueprint. This action allocates the physical devices, IP addresses, VLANs, and ASNs to the logical devices, networks, and routing zones in the blueprint. Resources can be assigned manually or automatically by the Apstra system. Assigning resources ensures that the blueprint has all the necessary elements to generate the configuration and deploy the fabric5 .
• Assign user roles to the blueprint. This action is not required during the deploy phase. User roles are defined at the system level, not at the blueprint level. User roles determine the permissions and access levels of different users in the Apstra system. User roles can be system-defined or custom-defined .
• Assign interface maps to the blueprint. This action is not required during the deploy phase. Interface maps are defined at the design phase, not at the deploy phase. Interface maps are objects that map the logical interfaces of a logical device to the physical interfaces of a device profile. Interface maps enable the Apstra system to generate the correct interface configuration for each device in the fabric . References:
• Deploy
• Deploy Device
• Device Profiles
• Juniper Device Profiles
• Resources

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