The Istio CNI Node Agent is responsible for several things

- Install an Istio CNI plugin binary on each node's filesystem, updating that node's CNI config in e.g (`/etc/cni/net.d`), and watching the config and binary paths to reinstall if things are modified.

          - path: 'spec.template.spec.containers[0].volumeMounts[100]'
            value:
              mountPath: /mnt/path1
              name: my-volume-name
        - kind: Service
          name: istio-pilot
          patches:
          - path: spec.ports.[name:grpc-xds].port
            value: 15099 # OVERRIDDEN
```

#### Calico

For Calico, you must also modify the settings to allow source spoofing:

- if deployed by operator,  `kubectl patch felixconfigurations default --type='json' -p='[{"op": "add", "path": "/spec/workloadSourceSpoofing", "value": "Any"}]'`

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Istio is an open source service mesh that layers transparently onto existing distributed applications. Istio’s powerful features provide a uniform and more efficient way to secure, connect, and monitor services. Istio is the path to load balancing, service-to-service authentication, and monitoring – with few or no service code changes.

- For in-depth information about how to use Istio, visit [istio.io](https://istio.io)