Exam AWS Certified Solutions Architect - Associate SAA-C02 topic 1 question 515 discussion

B https://docs.aws.amazon.com/vpc/latest/userguide/working-with-vpcs.html Associate a secondary IPv4 CIDR block with your VPC You can add another IPv4 CIDR block to your VPC. Ensure that you have read the applicable restrictions. After you've associated a CIDR block, the status goes to associating. The CIDR block is ready to use when it's in the associated state. The Amazon Virtual Private Cloud Console provides the status of the request at the top of the page. To add a CIDR block to your VPC using the console Open the Amazon VPC console at https://console.aws.amazon.com/vpc/ . In the navigation pane, choose Your VPCs. Select the VPC, and then choose Actions, Edit CIDRs. Choose Add new IPv4 CIDR. Enter the CIDR block; for example, 10.2.0.0/16. Choose Save. Choose Close. To add a CIDR block using a command line tool associate-vpc-cidr-block (AWS CLI) Register-EC2VpcCidrBlock (AWS Tools for Windows PowerShell) After you've added the IPv4 CIDR blocks that you need, you can create subnets. For more information, see Create a subnet in your VPC.

A: New VPC without VPC Peering? B: Correct C: You cannot increase or decrease the size of an existing CIDR block. D: With VPC Peering, two CIDRs should not overlap. New VPC's CIDR will overlap with the existing VPC's CIDR 10.10.1.0/24. https://docs.aws.amazon.com/vpc/latest/userguide/configure-your-vpc.html#vpc-sizing

Why C cant be the answer, it can give us more Ip address than /24? Please if anyone can explain, B also seems ok but why will we create another secondary VPC.

we can either: Add an additional IPv4 CIDR block as a secondary CIDR to VPC. -or- Create a new VPC with your preferred CIDR block and then migrate the resources from your old VPC to the new VPC (if applicable). Option B looks promising but if you go through restrictions while attaching CIDR block, the given option doesn't go well https://docs.aws.amazon.com/vpc/latest/userguide/configure-your-vpc.html#add-cidr-block-restrictions A looks promising

A and B are confusing It's not possible to change or modify the IP address range of an existing virtual private cloud (VPC) or subnet. However, you can do one of the following: Add an additional IPv4 CIDR block as a secondary CIDR to your VPC. -or- Create a new VPC with your preferred CIDR block and then migrate the resources from your old VPC to the new VPC (if applicable). https://aws.amazon.com/premiumsupport/knowledge-center/vpc-ip-address-range/

To extend the IPv4 address range of your VPC, see Associating a secondary IPv4 CIDR block with your VPC.

You can't resize CIDRs after set it to VPC. You can remove or create new one. Solution: Associate secondary CIDR block to VPC. https://docs.aws.amazon.com/vpc/latest/userguide/working-with-vpcs.html#add-ipv4-cidr

Why not C?

B - add another CIDR

BBBBBB

It's B

B is the correct answer.

Why not C ? it take less effort

B is better than A. Cos LEAST amount of operation overhead.

B https://aws.amazon.com/premiumsupport/knowledge-center/vpc-ip-address-range/