Migrating from an IPv4 network to an IPv6 network

Here are several resources:

1. Dual-stack IPv6 architectures for AWS and hybrid networks
2. Migrate existing VPCs from IPv4 to IPv6
3. IPv6 on AWS, Best practices for adopting and designing IPv6 on AWS

As with other services and scenarios, the answer would depend on the current usage of IPv4 internal and external resources. Sometimes the adoption strategy could be driven by extensive IPv6 user adoption in certain geographies, which will require an Outside-In approach as described in the following article: https://community.aws/content/2b4t5Yzxkj287f0xA6EfhVkKcrV/ipv6-adoption-strategies-on-aws

In some other scenarios, the strategy could be an Inside-Out driven by severe private IPv4 exhaustion thus leveraging dual stack VPCs and IPv6 only subnets. Proper routing should be considered where the use of Egress Only Internet Gateways allow proxying traffic to the internet from IPv6 hosts and, NAT64 and DNS64 extensions should enabled where backward compatibility to IPv4 services is needed.

As far as AWS services supporting IPv6 natively or dual stacked, a catalog can be consulted here: https://docs.aws.amazon.com/vpc/latest/userguide/aws-ipv6-support.html