Enable VPC-native (alias IP) on an existing GKE cluster
Is there a way to enable Alias IP on existing GKE cluster (with disabled Alias IP)?
(Besides using https://github.com/bowei/k8s-custom-iptables to create NATs on each node)
As per GCP VPC-native cluster's documentation, A cluster that uses Alias IPs is called a VPC-native cluster, and you cannot migrate a routes-based cluster to a VPC-native cluster. There is already a feature request for this. You would have to recreate the cluster or as you have mentioned, configure manual routes with NATs to get it working.