300-620 Exam Dumps : Implementing Cisco Application Centric Infrastructure (300-620 DCACI)

 In the scenario where Server2 information is missing from the Leaf 101 endpoint table and the COOP database of the spine, setting Layer 2 Unknown Unicast to Flood (Option B) is the correct action to meet the requirements. This setting will cause the ACI fabric to flood unicast packets destined for unknown destinations within the bridge domain. This ensures that packets from Server1 will reach Server2 even though its location isn’t known by Leaf 101 or the spine’s COOP database. frastructure/white-paper-c11-739989.html

To configure a Cisco ACI system to detect network loops for both untagged and tagged traffic and to stop the loop by disabling an interface within 4 seconds, the following configuration must be used:

Enable Mis-Cabling Protocol (MCP): MCP detects loops from external sources and will err-disable the interface on which Cisco ACI receives its own packet. This is crucial for preventing loops in the network1.

Configure MCP Transmit Frequency: Set the MCP transmit frequency to a value that allows for quick loop detection. The Cisco ACI fabric provides faster loop detection with transmit frequencies from 100 milliseconds to 300 seconds. To meet the requirement of detecting and stopping a loop within 4 seconds, you would set the transmit frequency to a value less than 4 seconds2.

Set Action on Loop Detection: Configure the MCP policies to identify loops and decide how to act upon them. You can set the policy to generate a syslog message or disable the port upon loop detection2.

Implement Error Disabled Recovery Policy: Configure an error disabled recovery policy to automatically re-enable ports that were disabled due to loop detection after a configurable interval2.

By implementing these configurations, the Cisco ACI system will be able to detect and stop network loops quickly and efficiently, ensuring network stability and preventing potential disruptions.

References :=

Cisco APIC Online Help - Loop Detection2

Cisco ACI Best Practices Quick Summary