GARP Based Endpoint Movement Detection in ACI

 GARP Based Endpoint Movement Detection

--> Cisco ACI by default can learn the Endpoint Movement between Leaf Switches or Leaf Ports or Endpoint Groups.

w--> Cisco ACI can not learn Endpoint Movement within the Same EPG and Same Interface.

--> When the GARP-based movement detection option is enabled then Cisco ACI will learn endpoint movement within the Same EPG and Same Interface.

--> By default, This option is disabled on the Cisco ACI.

--> In order to enable this option, You need to enable "Unicast Routing" and "ARP Flooding" on the Bridge Domain.

--> This scenario is basically recommended in case of "Failover" or VM movement within the same ESXi Host.

--> In the above Picture, There are Virtual Machines running on the ESXI Host and connected to Leaf Switch.

--> The problem here, If Virtual Machine 1 is currently running on the ESXI Host with the IP address 192.168.1.1

--> If shutdown this virtual machine1 and assign the IP address (192.168.1.1) to a different Virtual Machine then the traffic will blackhole as the ACI did not update the MAC address of the IP address (192.168.1.1)

 

--> We can prevent this issue by enabling " GARP Based Endpoint Movement Detection" under the Bridge Domain.

Reference:

https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/white-paper-c11-739989.html#EndpointDataplaneLearning