UnknownMeshNetworksServiceRegistry

Message Name	UnknownMeshNetworksServiceRegistry
Message Code	IST0126
Description	A service registry in Mesh Networks is unknown
Level	Error

This message occurs when a network in the mesh networks configuration has an endpoint with a fromRegistry value that Istio does not recognize.

The known service registries are Kubernetes, External, and the cluster IDs of the remote clusters that have a remote secret (a Secret with the label istio/multiCluster: "true").

An example

Consider a mesh networks configuration that references a registry named cluster2, but there is no remote secret for cluster2:

networks:
  network1:
    endpoints:
    - fromRegistry: cluster2
    gateways:
    - address: 192.0.2.10
      port: 15443

You will receive this message:

Error [IST0126] (MeshNetworks istio-system/meshnetworks) Unknown service registry cluster2 in network network1

How to resolve

Make sure that the fromRegistry value is the same as the cluster ID of the remote cluster.
Make sure that a remote secret exists for that cluster. You can create one with istioctl create-remote-secret.

For more information, refer to Install Multicluster.