JN0-480 Questions Bank

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

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)

 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