ACI BGP Route Reflector Policy

ACI BGP Route Reflector Policy

Question

Which two statements about the ACI BGP route reflector policy are true? (Choose two.)

Answers

Explanations

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A. B. C. D. E.

CD.

The ACI (Application Centric Infrastructure) is a software-defined networking (SDN) architecture that provides centralized automation and policy-based management of the data center network. The ACI fabric is built on top of a spine-leaf topology, where the spine switches connect to the external networks, and the leaf switches connect to the endpoints, such as servers and storage devices.

In the ACI fabric, BGP (Border Gateway Protocol) is used as the routing protocol to exchange routes between the spine switches and the leaf switches. BGP route reflectors (RRs) are used to reduce the complexity and improve the scalability of the BGP routing. The RR acts as a central point that reflects the BGP routes to other switches in the fabric.

Here are the correct statements about the ACI BGP route reflector policy:

B. Configuring route reflectors requires designating spines as route reflectors and providing the AS number.

To configure the ACI fabric to use BGP route reflectors, you need to designate some of the spine switches as the RRs and provide the Autonomous System (AS) number that is used for the BGP routing. The AS number is a unique identifier that is used to differentiate between different BGP domains.

D. The BGP route reflector domain policy autonomous system number is configured during the initial APIC setup script, but it can be modified afterward.

During the initial setup of the ACI fabric, you need to configure the BGP route reflector domain policy AS number in the APIC (Application Policy Infrastructure Controller) setup script. However, you can modify this setting later on if needed.

A, C, and E are incorrect statements:

A. Route reflectors need not configure connectivity to external networks, but slight performance degradation can occur between border leaf and compute node leafs.

This statement is incorrect because the RRs need to have connectivity to the external networks to receive the external BGP routes. However, there might be some performance degradation between the border leaf and the compute node leafs due to the additional BGP reflection process.

C. The ACI Fabric route reflectors use multiprotocol BGP to distribute external routes within the fabric.

This statement is incorrect because the ACI Fabric RRs use standard BGP to distribute the external BGP routes within the fabric. Multiprotocol BGP is used for other purposes, such as MPLS VPNs.

E. The BGP route reflector policy is configured under Fabric > Access Policies.

This statement is incorrect because the BGP route reflector policy is not configured under the Fabric > Access Policies menu. Instead, it is configured under the Fabric > Fabric Policies > Policies menu.

In summary, configuring BGP route reflectors in the ACI fabric requires designating some of the spine switches as RRs and providing the AS number. The BGP route reflector domain policy AS number is configured during the initial APIC setup script, but it can be modified afterward. The ACI Fabric RRs use standard BGP to distribute the external BGP routes within the fabric.