An organization launched an IPv6-only web portal to support IPv6-native mobile clients.

An organization launched an IPv6-only web portal to support IPv6-native mobile clients. Front-end instances launch in an Amazon VPC associated with an appropriate IPv6 CIDR. The VPC IPv4 CIDR is fully utilized. A single subnet exists in each of two Availability Zones with appropriately configured IPv6 CIDR associations. Auto Scaling is properly configured, and no Elastic Load Balancing is used.

Customers say the service is unavailable during peak load times. The network engineer attempts to launch an instance manually and receives the following message: “There are not enough free addresses in subnet ‘subnet-12345677’ to satisfy the requested number of instances.”

What action will resolve the availability problem?