Exam AWS Certified Advanced Networking - Specialty ANS-C01 topic 1 question 214 discussion

D - This meets the requirements and is the solution. The others would not work and CF will rebuild the subnet if provisioned.

A. Cannot update CIDR of the existing subnet B. Cannot update CIDR of the existing subnet C. Not recommended for IP Reassignment

This is D

this is D

Answer is A

By creating a new subnet with a different CIDR block (10.10.2.0/24) within the same Availability Zone, you can expand the IP address space available for that AZ without altering existing configurations. This approach is straightforward and minimizes the risk of disruption to the existing resources. This option allows you to quickly and easily increase the available IP space without needing to modify or replace existing subnets, which could cause service disruptions or require reassigning resources within the AZ. It avoids the complexities and potential issues associated with resizing subnets or VPCs, which can be more involved and risky. Changing the CIDR block of an existing subnet is not supported directly because subnets cannot be resized or modified after creation. Doing so would require deleting and recreating the subnet, which would disrupt any resources tied to it.