Cisco 300-620 - Implementing Cisco Application Centric Infrastructure (300-620 DCACI)

o protect the ACI fabric from spanning-tree loops, the feature that must be enabled on the ACI leaf ports is BPDU Guard 

The characteristic of Cisco ACI Multi-Pod that makes it unsuitable for deploying three separate data centers is that it requires all pods to share the same Cisco APIC cluster. In a Multi-Pod deployment, all the pods are part of the same fabric and are managed by a single APIC cluster, which means that they are not completely isolated from each other.

To complete the task of configuring a Layer 3 connection to the WAN router and allowing hosts in the production VRF to access WAN subnets, the engineer should configure the Export Route Control Subnet scope for the external EPG. This setting allows the subnets associated with the external EPG to be advertised to external routers, enabling connectivity to the WAN.

In a Cisco ACI Multi-Pod architecture, multiple pods (each with its own leaf-and-spine topology) are interconnected via an Inter-Pod Network (IPN). The key characteristic of the Multi-Pod setup is that it is managed as a single fabric by a single APIC cluster, simplifying operations and maintaining consistency across all pods.

MisCabling Protocol (MCP) detects loops from external sources (i.e., misbehaving servers, external networking equipment running STP, etc.) and will err-disable the interface on which ACI receives its own packet. Enabling this feature is a best practice, and it should be enabled globally and on all interfaces, regardless of the end device. For MCP to be enabled, you need to have it enabled globally and on a per-interface basis. While MCP is enabled on all interfaces by default, it is not turned “on” until you also enable it globally. The global configuration knob for MCP can be enabled by configuring the global settings here: Fabric > Access Policies > Global Policies > MCP Instance Policy default. https://www.cisco.com/c/dam/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/aci-guide-using-mcp-mis-cabling-protocol.pdf

 To allow multiple external networks to communicate with internal ACI subnets and assign the prefix to the class ID of the external Endpoint Group, the engineer should configure subnets with the External Subnets for External EPG flag enabled1. This configuration allows the specified subnets to be associated with an external EPG, which facilitates communication between internal tenants and external routed networks via L3Outs1.

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/aci/apic/sw/1-x/ACI_Best_Practices/b_ACI_Best_Practices/b_ACI_Best_Practices_chapter_01001.html

To support cross-site connectivity in a production Multi-Site solution, where connectivity from EPGs from a specific site to networks reachable through a remote site L3OUT is required, the additional configuration that must be implemented in the Multi-Site Orchestrator is to add a new stretched external EPG to the existing L3OUT1. This allows the EPGs from one site to communicate with the networks defined in the L3OUT at the remote site, facilitating the required connectivity across sites.

References :=

Cisco ACI Multi-Site Configuration Guide1

To securely export Cisco APIC configuration snapshots to a secure, offsite location using an encrypted tunnel and a platform-agnostic data format that provides namespace support, the following configuration set must be used:

Choose a Platform-Agnostic Data Format: Export the configuration in a data format like JSON or XML, which are platform-agnostic and support namespaces1.

Use an Encrypted Tunnel: Transfer the configuration snapshot over a secure protocol such as SFTP or SCP, which provides an encrypted tunnel for the data transfer1.

Schedule the Export: Set up a scheduled export of the configuration in the Cisco APIC to occur at regular intervals, ensuring the process is automated1.

Enable Encryption: Make sure the configuration export policy includes encryption settings. Cisco APIC supports AES-256 encryption for securing exported configuration files2.

Verify Namespace Support: Ensure that the chosen data format and the method of export support the use of namespaces, which are essential for organizing elements and attributes in XML documents1.

By following these steps and choosing Option B, the engineer can meet the requirements for securely exporting Cisco APIC configuration snapshots to an offsite location.

To advertise a bridge domain subnet out of the ACI fabric to an OSPF neighbor, the following configuration steps are required:

Configure Subnet scope to Advertised Externally: This step involves setting the scope of the subnet within the bridge domain to be advertised externally, which allows the subnet to be propagated to external routing entities3.

Add L30ut profile to the bridge domain using Associated L30uts section: This step involves associating the bridge domain with an L3Out profile, which is necessary for the bridge domain subnet to be advertised to OSPF neighbors4.

https://community.cisco.com/t5/documentos-data-center/configuraci%C3%B3n-snmp-para-aci/ta-p/4680520