What is a characteristic of a stretched bridge domain solution between Cisco ACI sites with...

 In a stretched bridge domain solution between Cisco ACI sites with Layer 2 flood enabled, spine head-end replication is utilized to forward Broadcast, Unknown unicast, and Multicast (BUM) traffic between the sites. This method leverages the spine switches at each site to replicate BUM traffic to other sites, ensuring that all endpoints within the stretched bridge domain can receive such traffic. This approach is chosen over ISN multicast replication because it simplifies the overall design and reduces bandwidth consumption on inter-site links by avoiding unnecessary duplication of BUM traffic. References := ( Implementing Cisco Application Centric Infrastructure Official Cert Guide )