prefix-assignment

doc

https://docs.aws.amazon.com/eks/latest/userguide/cni-increase-ip-addresses.html

When configured for prefix assignment, the CNI add-on can assign significantly more IP addresses to a network interface than it can when you assign individual IP addresses

• cni version 1.9.0 or over
• Enable the parameter to assign prefixes to network interfaces for the Amazon VPC CNI DaemonSet

kubectl describe ds aws-node -n kube-system |grep -i PREFIX
kubectl set env daemonset aws-node -n kube-system ENABLE_PREFIX_DELEGATION=true