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1. A solution architect is designing a new data center using Apstra and wants to follow Juniper's reference architecture. The architect plans to use a 3-stage Clos fabric with dedicated border leaf switches.

What is the primary role of the border leaf switches in this reference design?

2. A solution architect is presenting the Juniper Apstra architecture to a customer. The architect needs to explain the function of the main components.

What is the primary role of the Apstra server in the architecture?

3. A data center architect has to choose between two common EVPN-VXLAN overlay models for a new fabric: Centrally-Routed Bridging (CRB) and Edge-Routed Bridging (ERB).

In a CRB architecture, where is the Integrated Routing and Bridging (IRB) interface for a given tenant's VLAN located?

4. A network operator is provisioning a new tenant in a multi-tenant EVPN-VXLAN data center. The tenant requires two separate Layer 2 domains, VLAN 10 and VLAN 20. The operator needs to configure the VRF for this tenant.

What is the primary function of the Route Distinguisher (RD) in the VRF configuration?

routing-instances {

TENANT-C {

instance-type vrf;

interface irb.10;

interface irb.20;

route-distinguisher 10.1.1.1:300;

vrf-target target:65001:300;

}

}

5. In a spine-leaf fabric, a leaf switch is connected to four spine switches. The underlay uses EBGP, and the leaf has learned a route to a remote VTEP's loopback address from all four spines. The paths are all equal cost.

A traffic flow is initiated from a server connected to the local leaf to a server connected to the remote VTEP. The flow consists of multiple TCP sessions between the same source and destination IP addresses but with different source and destination ports.

How does Equal Cost Multi-Path (ECMP) load balancing typically distribute these TCP sessions across the four available paths to the spines?

6. A network engineer is configuring a new EVPN-VXLAN fabric. The underlay is established using EBGP, and all VTEPs have IP reachability to each other's loopback addresses. The overlay will also use BGP to exchange EVPN routes.

How should the overlay BGP sessions be configured between the leaf VTEPs?

7. A solution architect is explaining the benefits of using a data center reference design, such as a Juniper Validated Design (JVD), to a customer.

Which of the following are key benefits of building a network based on a reference design? (Select all that apply.)

8. A systems administrator is configuring a new data center fabric with EVPN-VXLAN. For a specific tenant VRF, the administrator needs to ensure that routes from this VRF are advertised to other VTEPs but also that this VRF can receive routes from a shared services VRF located elsewhere in the fabric.

Which combination of `vrf-import` and `vrf-export` policies would achieve this?

9. When configuring an EVPN-VXLAN fabric, there are two primary options for the control plane: MP-BGP EVPN and multicast.

What are the key differences and trade-offs between these two control plane options? (Select all that apply.)

10. A network issue occurred at 2:00 AM, and an engineer is now investigating the incident at 9:00 AM. The engineer suspects that a configuration change made around that time was the root cause.

Which Apstra feature allows the engineer to go back in time to view the exact state of the network's topology, configuration, and anomalies as they were at 2:00 AM?

11. An Operations Engineer has been tasked with managing an Apstra-managed fabric. A key part of the daily workflow is to check for any deviations from the intended state.

Which two features in the Apstra UI would be the primary tools for this daily health check? (Choose 2.)

12. An operator is reviewing the event logs in Apstra after a network incident.

The logs show a series of events in the following order:

1. "Link down" anomaly on interface et-0/0/1 of leaf-1.

2. "BGP session down" anomaly for the session between leaf-1 and spine-1.

3. "Route count" anomaly for the TENANT-A VRF on leaf-2.

4. "Application Unreachable" anomaly from a user-defined probe.

This correlation of events is a key feature of which Apstra concept?

13. 1.A DevOps engineer is using Apstra's Intent-Based Analytics (IBA) to investigate a report of intermittent high latency for an application. The engineer suspects that some links in the fabric might be overutilized due to suboptimal ECMP load balancing.

Which Apstra IBA feature would be most effective for verifying this suspicion?

14. A cloud architect is migrating a legacy 3-tier data center to a modern EVPN-VXLAN fabric. The new design follows Juniper best practices, using a 3-stage spine-leaf Clos architecture.

What is the primary benefit of this migration in terms of traffic flow and application performance?

15. A DevOps engineer notices that a specific flow between two servers is always using the same path through the spine-leaf fabric, even though four ECMP paths are available. The engineer wants to understand why other paths are not being used for this flow.

What is the fundamental reason for this behavior?

16. A systems administrator is troubleshooting a connectivity issue between two VMs, VM-A and VM-B, in an EVPN-VXLAN fabric. The administrator has confirmed that the underlying BGP sessions for the underlay and overlay are up and that both VMs can ping their default gateways (the IRB interfaces on their respective leaf switches).

The administrator checks the EVPN database on the local leaf switch (Leaf-A) where VM-A is connected, but does not see an entry for VM-B's MAC address.

user@Leaf-A> show evpn database

Instance: default-switch

VLAN VNI MAC address Active source Timestamp

100 10100 00:50:56:01:0A:01 vtep.32769 Oct 27 11:30:15

...

However, on the remote leaf switch (Leaf-B), the entry for VM-B is present.

user@Leaf-B> show evpn database

Instance: default-switch

VLAN VNI MAC address Active source Timestamp

100 10100 00:50:56:01:0B:02 vtep.32769 Oct 27 11:31:00

...

What is the most likely cause of this issue?

17. A network engineer is troubleshooting an EVPN-VXLAN fabric where hosts are unable to communicate with destinations outside the fabric. The fabric uses border leaf switches to connect to an external router.

The engineer checks the local leaf switch connected to a host and confirms it has learned the host's MAC/IP address. However, the `inet.0` table on the local leaf does not contain a default route.

The border leaf switch has the following configuration:

routing-instances {

TENANT-A-VRF {

instance-type vrf;

...

routing-options {

static {

route 0.0.0.0/0 next-hop 172.16.1.1;

}

}

vrf-export EXPORT-DEFAULT-POLICY;

}

}

policy-options {

policy-statement EXPORT-DEFAULT-POLICY {

term 1 from protocol static;

term 1 then {

community add COMM-DEFAULT;

accept;

}

}

community COMM-DEFAULT members target:65001:100;

}

The local leaf switch has a VRF import policy that accepts routes with the community `target:65001:100`.

What is the most likely reason the default route is missing on the local leaf switch?

18. A network architect is designing a large multi-tenant data center using EVPN-VXLAN. The architect must decide on the routing strategy for both the underlay and overlay networks. The goals are scalability, stability, and adherence to industry best practices.

Which combination of underlay and overlay routing strategies should be implemented?

19. A Network Operator needs to apply a set of user-defined labels to several leaf switches in an Apstra blueprint to signify their physical location (e.g., "DataHall-3, Row-B"). This will help with operational workflows and filtering in the UI.

What Apstra feature should the operator use to apply this metadata?

20. A solution architect is using Apstra to model a data center based on a Juniper reference design. The reference design calls for a specific logical topology where all server-facing leaf switches are identical and all border leaf switches are identical.

How does the architect enforce this consistency and reusability in the Apstra design?

21. When designing a new data center fabric in Apstra, an engineer needs to assign specific resources from a larger pool to different parts of the fabric. For example, the VTEP loopback IP addresses for racks 1-10 should come from one /24 range, while racks 11-20 should use a different /24 range.

How can the engineer achieve this granular allocation within Apstra's resource management?

22. A network operations engineer is troubleshooting an EVPN-VXLAN fabric where a host in VLAN 100 cannot communicate with a host in VLAN 200. Both hosts are connected to the same leaf switch (Leaf-1). The engineer suspects an issue with the Layer 3 routing configuration within the overlay. The fabric uses an Edge-Routed Bridging (ERB) model.

The engineer issues the following command on Leaf-1:

user@Leaf-1> show evpn database

Instance: default-switch

VLAN VNI MAC address Active source Timestamp

100 10100 00:0c:29:11:22:33 vtep.32769 Oct 27 10:20:15

200 10200 00:0c:29:44:55:66 vtep.32769 Oct 27 10:21:05

...

user@Leaf-1> show configuration routing-instances

TENANT-A {

instance-type vrf;

interface irb.100;

interface irb.200;

route-distinguisher 192.168.0.1:100;

vrf-target target:65001:100;

vrf-table-label;

}

Given this output, what is the most likely reason for the communication failure?

23. A NOC technician is investigating a BGP session flap that occurred overnight in an Apstra-managed fabric. The technician needs to find the exact time the anomaly was raised and see any related events that happened around the same time.

Which section of the Apstra UI is the primary source for this type of historical event and anomaly information?

24. An Operations Engineer is extending a Layer 2 domain between two racks in an EVPN-VXLAN fabric. A server in Rack 1, connected to Leaf-1, needs to be in the same subnet as a server in Rack 2, connected to Leaf-2.

What is the function of the EVPN Instance (EVI), also known as the `vlan-id` or `bridge-domain-id` in this scenario?

25. An EVPN-VXLAN overlay is running on top of a BGP-based IP fabric underlay. A network engineer needs to verify the control plane for the overlay.

Which of the following statements accurately describe the relationship between the underlay and overlay control planes? (Choose 2.)

26. In a multi-tenant EVPN-VXLAN data center, a security administrator needs to allow a specific shared service (e.g., a DNS server in a "services" VRF) to be accessible by all tenants, while still keeping the tenants isolated from each other.

Which EVPN features and techniques should be used to achieve this controlled route leaking? (Select all that apply.)

27. A cloud architect is designing a new data center fabric that will be managed by Juniper Apstra. The architect wants to follow Juniper's recommended best practices for building a scalable and resilient network.

Which of the following are considered Juniper Networks best practices for designing an Apstra-managed IP fabric? (Select all that apply.)

28. An automation engineer is using Juniper Apstra to design and deploy a new data center fabric. The engineer has already created the necessary templates, device profiles, and interface maps.

What is the next logical step the engineer must take in the "Build" phase of the Apstra workflow?

29. A NOC technician is verifying the operational state of an EVPN-VXLAN fabric. The technician needs to confirm the mapping between VLANs and their corresponding Virtual Network Identifiers (VNIs) on a leaf switch.

Which command would the technician use to display this information?

30. An architect is planning a large data center that will eventually grow to support thousands of servers, requiring more leaf switches than a single set of spines can support.

Which architectural evolution allows the data center to scale beyond a single 3-stage Clos fabric?