Elastic Network Interface

Answer - C.

The AWS documentation mentions the following on some of the points regarding Elastic Network Interfaces.

1)You can attach a network interface to an instance when it's running (hot attach), when it's stopped (warm attach), or when the instance is being launched (cold attach).

2)You can detach secondary (ethN) network interfaces when the instance is running or stopped.

However, you can't detach the primary (eth0) interface.

3)You can attach a network interface in one subnet to an instance in another subnet in the same VPC; however, both the network interface and the instance must reside in the same Availability Zone.

For more information on the Elastic Network Interface, please visit the below link:

http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-eni.html

The Elastic Network Interface (ENI) is a logical networking component in Amazon Web Services (AWS) that provides a virtual network interface card (NIC) for instances in a Virtual Private Cloud (VPC). It can be used to create a network interface for an instance, attach and detach network interfaces, and assign and unassign private IP addresses.

Let's analyze each answer option to determine which statement is false.

A. You can attach a network interface to an instance when it's running. This statement is true. You can attach an ENI to a running instance, and the instance can start using the network interface without any downtime.

B. You can detach the secondary network interface and attach it to another instance in the same subnet. This statement is true. You can detach a secondary ENI from an instance and attach it to another instance in the same subnet.

C. You can detach the primary network interface and attach it to another instance in the same subnet. This statement is false. You cannot detach the primary network interface from an instance, as it is the default network interface for the instance. You can attach secondary network interfaces to an instance, but you cannot remove the primary network interface.

D. You have a secondary private IP for a Network Interface. This statement is true. You can assign one or more private IP addresses to a secondary ENI, and you can use those private IP addresses to communicate with other resources in the VPC.

Therefore, the answer is (C). You cannot detach the primary network interface from an instance and attach it to another instance in the same subnet.