JPR-981 JNCIE-DC Practice Questions
Prepare for JPR-981 with more than an answer.
- 1
Case Study:
Company XYZ is deploying a new Data Center using Juniper Apstra. The design calls for a 3-stage Clos fabric.
Requirement 1: All leaf switches must have a specific 'motd' banner warning against unauthorized access.
Requirement 2: This banner is not part of the standard Apstra logical device or interface map.
Requirement 3: The banner text might change quarterly, so it should be easily updatable across the entire fabric.Which Apstra workflow best satisfies these requirements?
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Correct answer: D
A 'System' style Configlet is appropriate for top-level configurations like banners (system hierarchy). Importing it into the Blueprint and applying it allows for centralized management. Editing the Configlet within the Blueprint (or updating from the Global Catalog) allows for easy quarterly updates.
- 2
When configuring a controllerless IP fabric with EBGP, you want to ensure that if a leaf switch loses all its uplinks to the spines, it automatically shuts down its server-facing interfaces to preventing blackholing traffic. Which feature should be enabled?
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Correct answer: A
Uplink Failure Detection (UFD) monitors the status of uplink interfaces. If the number of active uplinks falls below a threshold (usually 0), it automatically disables the downstream server-facing ports. This forces the servers to NIC failover to the other redundant leaf switch.
- 3
You are defining an import policy for a VRF in an EVPN environment. You want to import routes that have a specific Route Target (target:65000:100). Which command correctly defines this policy term?
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Correct answer: A
In Junos policy-options, you match extended communities (like Route Targets) using the 'from community' statement. You must first define the community name (e.g., 'set policy-options community tenant-a members target:65000:100') and then reference it, or reference the literal value if supported in newer versions, but typically it's 'from community '.
- 4
A network architect is designing a new controllerless IP Fabric using EBGP for the underlay. To ensure proper load balancing across all spine links, the architect must configure the forwarding table export policy. Which specific action must be applied to the load-balancing policy to ensure per-flow load balancing is active across equal-cost paths?
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Correct answer: D
In Junos, to enable ECMP (Equal-Cost Multipath) load balancing, you must define a policy that sets the action 'load-balance per-flow' and apply this policy to the forwarding table via 'set routing-options forwarding-table export '. Without this, Junos installs only one next-hop in the forwarding table even if multiple routes exist in the routing table.
- 5
You are managing a Juniper Apstra environment and need to ensure that a specific configuration snippet for an NTP server is applied to all Leaf switches in a specific Blueprint. This configuration is not natively modeled by the Apstra reference design. Which mechanism should you use?
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Correct answer: C
Configlets in Juniper Apstra are small snippets of configuration text (CLI) used to deploy configurations that are not covered by the standard Reference Design (Blueprint). You create the Configlet in the Global Catalog and then import/apply it to the specific Blueprint and devices.
- 6
In an EVPN-VXLAN environment, you are configuring an ESI-LAG for a multi-homed server connected to two QFX switches. You want to ensure that if the link on one switch fails, traffic is rapidly switched to the other link without waiting for BGP protocol convergence. Which EVPN route type is primarily responsible for the 'Aliasing' function that enables load balancing to both switches even if one switch hasn't advertised specific MAC addresses yet?
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Correct answer: B
EVPN Type 1 routes (Ethernet Auto-Discovery) are used for Aliasing and Mass Withdrawal. The A-D per EVI route advertises the reachability of the ESI. Remote VTEPs use this to load balance traffic to all VTEPs sharing the same ESI, even if a specific MAC (Type 2) has only been learned/advertised by one of the PE devices, a feature known as Aliasing.
