How do I change the subnet mask for the default subnet of my default Amazon VPC?

Short description

You can delete the default subnet for your default VPC and replace it with customized configurations.

Resolution

1. Delete the default subnet for your default Amazon VPC in an AWS Region.
2. Create a new subnet with your preferred subnet mask size. Be sure that the new subnet is part of your default VPC in the same AWS Region.
   Note: The first four IP addresses and the last IP address in each subnet CIDR block aren't available for your use. These IP addresses can't be assigned to an instance.

Related information

Delete your default subnets and default VPC

How Amazon VPC works