You currently have EC2 Instances in a private subnets. There are applications based on IPv6 which are hosted on these instances. You have configured NAT instances in a public subnet to ensure that applications hosted on the instances in the private subnet can download the required updates. But after configuring the instances , the applications are still not able to download the updates. Which of the following could be the underlying issue.

Answer options:

A.The NAT instance should not be configured in the public subnet , it should be configured in the private subnet
B.The NAT instance is not configured with a private IP address.
C.NAT is not supported for IPv6 traffic
D.The NAT instance is not configured with a private DNS name.

Answer - C
The AWS documentation mentions the following
NAT is not supported for IPv6 traffic—use an egress-only Internet gateway instead.
For more information on NAT Instances, please visit the link:
http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/VPC_NAT_Instance.html