300-630 Exam Dumps : Implementing Cisco Application Centric Infrastructure - Advanced (DCACIA)

The minimum MTU value that must be supported by the ISN to allow control plane endpoint information exchange between sites in a Cisco ACI Multi-Site setup with default settings is 1554 bytes (B). This accounts for the standard MTU of 1500 bytes plus additional overhead for VXLAN encapsulation. An MTU of 9000 (A) or 9100 © is not the minimum required, and 1600 (D) is not related to the default fabric settings5. References := (Multi-site / Multi-Pod MTU Jumbo Frames5)

 In Cisco ACI fabric, STP BPDUs are flooded in the bridge domain VLAN. This allows the BPDUs to be propagated throughout the fabric, maintaining the STP topology2.

References := Implementing Cisco Application Centric Infrastructure Official Cert Guide

When traffic to certain endpoints is dropped in a Cisco ACI fabric configured with hardware proxy, setting the L2 Unknown Unicast option to Flood for Layer 2 switched traffic can prevent this problem. This mode allows unknown unicast traffic to be flooded within the bridge domain, rather than being sent to the spine proxy and potentially discarded if the destination is unknown5.

References := Solved: Unknown Unicast in ACI Fabric - Cisco Community