AWS Certified Advanced Networking Specialty Practice Exam

What action should be taken to migrate VPC instances from 192.168.0.0/16 to 10.0.0.0/16?

1. Create a new VPC and migrate existing workloads.

2. Change the CIDR of the existing VPC.

3. Update the routing tables only.

4. Migrate using Amazon VPC peering.

The correct answer is: Create a new VPC and migrate existing workloads.

Creating a new VPC and migrating existing workloads is the appropriate action for migrating instances from one CIDR block (192.168.0.0/16) to another (10.0.0.0/16). This is because AWS does not allow you to change the CIDR block of an existing VPC once it has been created. Therefore, if you need to move resources from one IP address range to another, the most effective way is to set up a new VPC that utilizes the desired CIDR block. After creating the new VPC, the workloads can be migrated through various methods such as creating AMIs of the instances and launching them in the new VPC, or using services like AWS Application Migration Service or AWS DataSync, depending on the workload type. The other approaches outlined in the choices would not achieve the goal of changing the IP address range of the VPC effectively. For example, attempting to update routing tables alone does not address the underlying CIDR change. Similarly, while VPC peering can connect multiple VPCs, it does not facilitate the transfer of workloads between CIDR blocks and is not applicable for a migration scenario where the goal is to change the IP address space of the existing resources.