Application Load Balancer (ALB) now allows customers to provision load balancers without IPv4s for clients that can connect using just IPv6s. To connect, clients can resolve AAAA DNS records that are assigned to ALB. The ALB is still dual stack for communication between the load balancer and targets. With this new capability, you have the flexibility to use both IPv4s or IPv6s for your application targets, while avoiding IPv4 charges for clients that don’t require it. To get started, you can either create a new dual-stack ALB without public IPv4 or modify existing ALBs to use dual-stack without public IPv4 using AWS APIs or console. There are no additional charges for using this feature. The internet facing Ipv6 only ALB is now available in all commercial AWS Regions, and the AWS GovCloud (US) Regions.
Source:: Amazon AWS