### Human: Can you tell about VM power on failure on Nutanix Cloud Clusters (NC2) on AWS. Error: Failed to PlugNic. ### Assistant: Sharing AWS subnets between multiple NC2 or reusing the AWS subnets results in VM power On task failure.. NC2 does not support the sharing of the same AWS subnet among multiple clusters and reusing of AWS subnets. Other instances or services in the VPC may occupy IP addresses in AHV's pool of IPs. The AWS EC2 API does not provide a method to list used/available IP addresses.If you reuse or share AWS subnets in a cluster or among multiple clusters, Powering on or migrating VM may result in a failure with the message as in the screenshot:Log messages in /home/nutanix/data/logs/acropolis.out on CVM reports on "Failed to PlugNic":
nutanix@NTNX-i-0XXXXXXXXXXX-A-CVM:x.x.x.186:~$ allssh 'grep "Failed to PlugNic for IP" /home/nutanix/data/logs/acropolis.out'. Scenario 1. Multiple NC2 are sharing of the same AWS subnet
Nutanix Cluster A is using Subnet A. VM in the cluster is connected to Subnet ANutanix Cluster B is configured with a Network with Subnet AFailure to power on a VM in Nutanix Cluster B
Solution for Scenario 1

Connect all VMs in Nutanix Cluster A a subnet other than Subnet A. Alternatively, delete all VMs in Nutanix Cluster A.Delete Network with Subnet A via Prism Web Console in Nutanix Cluster A.Run the command from one of the CVM in Nutanix Cluster A:
	nutanix@CVM:~$ hostssh 'cloudnet forcerun-gc br0.uvms'
	Power on VM in Nutanix Cluster B
Scenario 2. Reusing AWS subnets in NC2

Nutanix Cluster used to use Subnet A in the pastNutanix Cluster is configured with a Network with Subnet AFailed to power on VM in the Nutanix Cluster
Solution for Scenario 2

Connect all VMs in Nutanix Cluster A  to a subnet other than Subnet A. Alternatively, delete all VMs in the Nutanix ClusterDelete Network with Subnet A via Prism Web ConsoleRun the command from one of the CVM in Nutanix Cluster
	nutanix@CVM:~$ hostssh 'cloudnet forcerun-gc br0.uvms'
	Create a Network with Subnet A via Prism Web ConsoleConnect VM in Nutanix Cluster A to Subnet APower on VM in Nutanix Cluster
Scenario 3. IP address occupied by non-Nutanix instance or other AWS object/service in the VPC.

Nutanix Cluster is configured with a Network with Subnet ACustomer adds a non-Nutanix AWS instance, a transit gateway, or other AWS object or service endpoint in the same VPCFailed to PlugNic error similar to the following is seen: 
	nutanix@CVM:~$ hostssh 'cloudnet forcerun-gc br0.uvms'
	
Solution for Scenario 3

Confirm the IP address is used intentionally (should be identifiable from AWS console. The error message above will identify the ENI in the InterfaceID field. Run the command from one of the CVM in Nutanix Cluster, to blacklist the IP reported in the error.
	nutanix@CVM:~$ hostssh 'cloudnet forcerun-gc br0.uvms'
	Retry the operation.
Note: The command cloudnet forcerun-gc br0.uvms is non-disruptive to the running UVMs. It cleans up ENIs that are not in use by UVMs. This is a per-host command therefore the need to do the command with the hostssh. If you only have issues with one host, you can also run the command on a single ahv host. . ### Human: Now explain this as a Nutanix support agent summarizing the answer step by step. In case, you don't know the answer say - I don't know.