Enable Dual Stack

Enable dual-stack support when your cluster is provisioned with both IPv4 and IPv6 addresses and you need services in the mesh to be reachable over both protocols.

To enable dual-stack support (IPv4 and IPv6) for the Istio service mesh, set enableDualStack to true in the istio-features ConfigMap. This configures Istio Pilot and all gateways to use RequireDualStack IP family policy and propagates the ISTIO_DUAL_STACK environment variable to all Envoy proxies.

When you enable this feature and the cluster load balancer is dual-stack, it has the following effects:

• Istio Pilot is configured with ISTIO_DUAL_STACK=true.
• Istio Pilot, ingress gateway, and egress gateway services use ipFamilyPolicy: RequireDualStack.
• Sidecar proxies receive ISTIO_DUAL_STACK=true via mesh config defaultConfig.proxyMetadata.

NOTE

This flag only takes effect when the cluster load balancer is also configured for dual-stack. The kyma-provisioning-info ConfigMap in the kyma-system namespace must exist and contain dualStackIPEnabled: true under networkDetails. If the kyma-provisioning-info ConfigMap is absent or the field is false, enabling dual-stack in the istio-features ConfigMap has no effect.

CAUTION

Enabling dual-stack is a one-way operation and cannot be reversed. Once enableDualStack is set to true and reconciliation runs, setting the flag back to false or deleting the ConfigMap doesn't revert the Services to single-stack.