Amazon has extensive guide on how to add IPv6 support to your VPC and EC2 instances. However there are issues with cloud-init package preserving IPv6 connectivity between reboots on CentOS.
AWS
Updating Amazon RDS SSL/TLS Certificates for Laravel application on CentOS
On October 9 Amazon sent out email to all customers with Amazon RDS instances titled “Update Your Amazon RDS SSL/TLS Certificates by October 31, 2019”. However the title is a bit misleading because the actual deadline is March 5, 2020.
