Cisco Updated 300-620 Exam Questions and Answers by kieran

To divert traffic between VM-1 and VM-2 using a Multi-Node service graph while preventing an insufficient number of available Layer 4 to Layer 7 devices in the first cluster, the following configuration set should be used:

PBR node tracking: This feature monitors the health of the nodes (Layer 4 to Layer 7 devices) in the service graph. If a node becomes unavailable, the system can take action based on the tracking threshold1.

Tracking threshold with action bypass: When the number of healthy nodes falls below the tracking threshold, the action ‘bypass’ ensures that traffic is not sent to the unhealthy nodes, thus preventing service disruption1.

Symmetric PBR: This ensures that return traffic follows the same path as the original traffic, maintaining session consistency and avoiding asymmetric routing issues1.

Resilient hashing: This hashing mechanism provides a consistent and optimal distribution of traffic across the available Layer 4 to Layer 7 devices, even when the number of nodes changes due to a failure or maintenance1.

References :=

Cisco APIC Layer 4 to Layer 7 Services Deployment Guide, Release 5.2(x)

The type of port used for in-band management within ACI fabric is the spine switch port4.

To meet the requirements for the new endpoint group’s bridge domain in the Cisco ACI fabric, the following actions must be taken:

Disable ARP Flooding: This action prevents ARP requests from being broadcast across the entire bridge domain, which reduces excessive broadcast traffic.

Enable Limit IP Learning to Subnet: This setting restricts IP address learning to only those IPs within the configured subnet, minimizing the impact of misconfigured virtual machines.

Enable Unicast Routing on the bridge domain and configure a subnet: Enabling unicast routing allows the bridge domain to function as the default gateway for the subnet, ensuring that routing remains within the Cisco ACI fabric.

 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 associatedwith 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