You’re trying to do some housekeeping and delete some unwanted interfaces. You try to delete an interface manually that has the following information.
{
"Status": "in-use",
 ...
"Description": "VPC Endpoint Interface vpce-08233123488812123",
"NetworkInterfaceId": "eni-c8fbc27e",
"VpcId": "vpc-1a2b3c4d",
"PrivateIpAddresses": [
{
"PrivateDnsName": "ip-20-0-2-227.ec2.internal",
"Primary": true,
"PrivateIpAddress": "20.0.2.227"
}
],
"RequesterManaged": true,
 ...
}
But you are not able to delete the interface. What is the reason that you cannot delete the interface?
 

Answer options:

A.It’s because it is a requester managed interface.
B.It’s because it has a private DNS name attached.
C.It’s because it has a private IP address attached.
D.It’s because it`s attached to a VPC.

Answer – A
The AWS Documentation mentions the following.
A requester-managed network interface is a network interface that an AWS service creates in your VPC. This network interface can represent an instance for another service, such as an Amazon RDS instance, or it can enable you to access another service or resource, such as an AWS PrivateLink service or an Amazon ECS task.
You cannot modify or detach a requester-managed network interface. If you delete the resource that the network interface represents, the AWS service detaches and deletes the network interface for you.
Options B, C and D are invalid because it’s not because of these attributes as to why the network interface can’t be deleted.
For more information on requester managed interfaces, one can visit the below URL
https://docs.aws.amazon.com/AWSEC2/latest/WindowsGuide/requester-managed-eni.html