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Kubernetes (and hence GKE) does not support multiple service ranges per cluster. You can only have a single, cluster-wide service range.
If you are trying to support multiple env in the same cluster and need some type of network isolation, I’d recommend either using a combination of namespaces and NetworkPolicy (where you can restrict who can talk to services) or potentially using a service mesh such as ASM or Istio.
I’d start with namespaces and NetworkPolicy as it’s less overhead.