A. OSPF

B. You need to configure a next-hop self policy.
D. You need to configure multipath multiple-as.

Answer DescriptionExplanation:

Issue Overview:

The leaf devices in an IP fabric using eBGP are advertising and receiving all routes, but the routes are not being installed in the routing table and are marked as hidden. Thistypically indicates an issue with the BGP configuration, particularly with next-hop handling or AS path concerns.

Corrective Actions:

B. You need to configure a next-hop self policy:This action ensures that the leaf devices modify the next-hop attribute to their own IP address before advertising routes to their peers. This is particularly important in eBGP setups where the next-hop may not be directly reachable by other peers.

D. You need to configure multipath multiple-as:This setting allows the router to accept multiple paths from different autonomous systems (ASes) and use them for load balancing. Without this, the BGP process might consider only one path and mark others as hidden.

Incorrect Statements:

A. You need to configure as-override:AS-override is used to replace the AS number in the AS-path attribute to prevent loop detection issues in MPLS VPNs, not in a typical eBGP IP fabric setup.

C. You need to configure loops 2:There is no specific BGP command loops 2 relevant to resolving hidden routes in this context. It might be confused with allowas-in, which is used to allow AS path loops under certain conditions.

Data Center References:

Proper BGP configuration is crucial in IP fabrics to ensure route propagation and to prevent routes from being marked as hidden. Configuration parameters like next-hop self and multipath multiple-as are common solutions to ensure optimal route installation and load balancing in a multi-vendor environment.

B. Each device in the underlay should advertise its loopback address.

B. EVPN
C. VMTO

A. drop
D. log
E. shutdown

Answer DescriptionExplanation:

MAC Move Limiting:

MAC move limiting is a security feature used in network switches to detect and mitigate rapid changes in MAC address locations, which could indicate a network issue or an attack such as MAC flapping or spoofing.

When a MAC address is learned on a different interface than it was previously learned, the switch can take various actions to prevent potential issues.

Available Actions:

A. drop:This action drops packets from the MAC address if it violates the move limit, effectively blocking communication from the offending MAC address.

D. log:This action logs the MAC move event without disrupting traffic, allowing network administrators to monitor and investigate the event.

E. shutdown:This action shuts down the interface on which the MAC address violation occurred, effectively stopping all traffic on that interface to prevent further issues.

Other Actions (Not Correct):

B. filter:Filtering is not typically associated with MAC move limiting; it generally refers to applying ACLs or other mechanisms to filter traffic.

C. enable:This is not an action related to MAC move limiting, as it does not represent a specific reaction to a MAC move event.

Data Center References:

MAC move limiting is crucial for maintaining network stability and security, particularly in environments with dynamic or large-scale Layer 2 networks where MAC addresses might frequently change locations.

B. The oversubscription ratio decreases when you add spine devices.
C. The oversubscription ratio increases when you remove spine devices.

Answer DescriptionUnderstanding Oversubscription in a Clos Fabric:

The oversubscription ratio in a Clos IP fabric measures the ratio of the amount of edge (leaf) bandwidth to the core (spine) bandwidth. An oversubscription ratio of 3:1 means that there is three times more edge bandwidth compared to core bandwidth.

Impact of Adding/Removing Spine Devices:

Option C:If youremove spine devices, the total available core bandwidth decreases, while the edge bandwidth remains the same. This results in anincrease in the oversubscription ratiobecause there is now less core bandwidth to handle the same amount of edge traffic.

Option B:Conversely, if youadd spine devices, the total core bandwidth increases. This decreases the oversubscription ratio because more core bandwidth is available to handle the edge traffic.

Conclusion:

Option C:Correct—Removing spine devices increases the oversubscription ratio.

Option B:Correct—Adding spine devices decreases the oversubscription ratio.

C. show interfaces terse vtep.32770 statistics

Answer DescriptionVXLAN Traffic Verification:

To ensure VXLAN traffic from the xe-0/0/12 interface is correctly encapsulated by the logical vtep.32770 and sent to a remote leaf device, it is essential to monitor the relevant interface statistics.

The command show interfaces terse vtep.32770 statistics provides a concise overview of the traffic statistics for the specific VTEP interface, which can help verify whether traffic is being correctly encapsulated and transmitted.

Explanation:

This command is particularly useful for quickly checking the traffic counters and identifying any potential issues with VXLAN encapsulation or transmission.

It allows you to confirm that traffic is flowing as expected, by checking the transmitted and received packet counters.

Data Center References:

Monitoring interface statistics is a crucial step in troubleshooting and validating network traffic, particularly in complex overlay environments like EVPN-VXLAN.

B. Design a three-stage Clos IP fabric.
D. Use OFX5700 Series devices as the super spines.

Answer DescriptionClos IP Fabric Design:

A Clos fabric is a network topology designed for scalable, high-performance data centers. It is typically arranged in multiple stages, providing redundancy, high bandwidth, and low latency.

Three-Stage Clos Fabric:

Option B:A three-stage Clos fabric, consisting of leaf, spine, and super spine layers, is widely used in data centers. This design scales well and allows for easy expansion by adding more leaf and spine devices as needed.

Super Spines for Scalability:

Option D:Using high-capacity devices like the QFX5700 Series as super spines can handle the increased traffic demands in large data centers and support future growth. These devices provide the necessary bandwidth and scalability for large-scale deployments.

Conclusion:

Option B:Correct—A three-stage Clos fabric is a proven design that addresses growth and scalability concerns in large data centers.

Option D:Correct—QFX5700 Series devices are suitable for use as super spines in large-scale environments due to their high performance.