JN0-480 Exam Dumps - Data Center Specialist (JNCIS-DC)

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Question # 4

You are working with a three-stage IP fabric using EBGP for peering.

In this scenario, which two actions are required to implement ECMP? (Choose two.)

Usea load balancing policy applied to the forwarding table as an export policy.

Use a load balancing policy applied to BGP as an export policy.

Use the multipath multiple-as BGP parameter.

Use a load balancing policy applied lo BGP as an import policy.

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Answer:

Explanation:

To implement ECMP in IP fabric using EBGP, you need to enable BGP to install multiple equal-cost paths in the routing table and to advertise them to the peers. The following actions are required to achieve this:

B. Use a load balancing policy applied to BGP as an export policy. This is true because you need to apply a load balancing policy to BGP as an export policy to allow BGP to advertise multiple paths to the same destination to the peers. By default, BGP only advertises the best path to the peers, which prevents ECMP. A load balancing policy can be configured to match the desired routes and set the multipath attribute to true. This will enable BGP to advertise up to the maximum number of paths configured by the maximum-paths command. For example, the following configuration applies a load balancing policy to BGP as an export policy for the neighbor 10.10.10.1:

policy-statement load-balance { term 1 { from { route-filter 192.168.0.0/16 exact; } then { multipath; accept; } } } protocols { bgp { group ebgp { type external; neighbor 10.10.10.1 { export load-balance; } } } }

C. Use the multipath multiple-as BGP parameter. This is true because you need to enable the multipath multiple-as BGP parameter to allow BGP to install multiple paths from different autonomous systems in the routing table. By default, BGP only installs multiple paths from the same autonomous system, which limits ECMP. The multipath multiple-as parameter can be configured under the BGP group or neighbor level. This will enable BGP to install up to the maximum number of paths configured by the maximum-paths command. For example, the following configuration enables the multipath multiple-as parameter for the BGP group ebgp:

protocols { bgp { group ebgp { type external; multipath multiple-as; } } }

The following options are incorrect because:

A. Use a load balancing policy applied to the forwarding table as an export policy is wrong because applying a load balancing policy to the forwarding table does not affect the BGP advertisement or installation of multiple paths. A load balancing policy applied to the forwarding table only affects how the traffic isdistributed among the multiple paths in the forwarding table. It does not enable ECMP in BGP.
D. Use a load balancing policy applied to BGP as an import policy is wrong because applying a load balancing policy to BGP as an import policy does not affect the BGP advertisement of multiple paths. A load balancing policy applied to BGP as an import policy only affects how the BGP routes are accepted or rejected from the peers. It does not enable ECMP in BGP.Â References:
IP Fabric Underlay Network Design and Implementation
Use ECMP to distribute traffic between two paths, one learned by eBGP and one learned by iBGP on a Cisco NX-OS switch
Example: Configure an EVPN-VXLAN Centrally-Routed Bridging Fabric Using EBGP

Question # 5

You have designed your fabric in Juniper Apstra prior to deploying the network devices.

Which Apstra element in the Staged tab would be used to assist the team that is installing and cabling the devices?

Connectivity Templates

Virtual Networks table

Managed Devices list

Links table

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Question # 6

Which three statements describe intent-based analytics? (Choose three.)

It indicates when device operating versions require updating.

It is a real-time information processing pipeline.

It is used to establish network performance baselines.

It alerts the network operator when network performance moves away from the baseline.

It collects information from vendor websites.

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Answer:

Explanation:

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.Â 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.Â 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.Â 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.Â 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.Â IBA only collects information from the devices in the network, using agents and probes1.

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