False Statements about VPC and IP Addressing

Answer - C.

The AWS documentation mentions the following.

If you have an existing VPC that supports IPv4 only, and resources in your subnet that are configured to use IPv4 only, you can enable IPv6 support for your VPC and resources.

Your VPC can operate in dual-stack mode - your resources can communicate over IPv4, or IPv6, or both.

IPv4 and IPv6 communication are independent of each other.

You cannot disable IPv4 support for your VPC and subnets; this is the default IP addressing system for Amazon VPC and Amazon EC2.

For more information on VPC and IP addressing , please visit the below URL:

http://docs.aws.amazon.com/AmazonVPC/latest/UserGuide/vpc-migrate-ipv6.html

The correct answer is B: "You cannot disable IPv4 support for your VPC" is false.

Explanation:

A Virtual Private Cloud (VPC) is a logically isolated section of the Amazon Web Services (AWS) Cloud where you can launch AWS resources in a virtual network that you define. Here are the statements and their explanations:

A. You can enable IPv6 support for your VPC and resources:

• This statement is true. AWS supports IPv6 for VPC and all the resources within the VPC, including Amazon EC2 instances, Elastic Load Balancers, and more.

B. You cannot disable IPv4 support for your VPC:

• This statement is false. While IPv4 is enabled by default for VPC and its resources, you can disable IPv4 support for your VPC by creating an IPv6-only VPC. However, it is not recommended to do so as many AWS services and features require IPv4.

C. You can only operate VPC's in only one mode at a time, either IPv4 or IPv6:

• This statement is true. You can operate your VPC in either IPv4 or IPv6 mode, but not in both modes simultaneously.

D. The default IP addressing for Amazon VPC and Amazon EC2 is IPv4:

• This statement is true. When you create a VPC, it is created with a default IPv4 CIDR block, which is a range of IP addresses in the IPv4 address space. When you launch an Amazon EC2 instance in a VPC, it is assigned a private IPv4 address within the VPC's IPv4 CIDR block.

In summary, the false statement is B. While IPv4 is enabled by default for VPC and its resources, you can disable IPv4 support for your VPC by creating an IPv6-only VPC.