ference/config/istio.mesh.v1alpha1/#MeshConfig-OutboundTrafficPolicy-Mode>mesh configuration</a>.</p><p>This is where the BlackHole and Passthrough clusters are used.</p><h2 id=what-are-blackhole-and-passthrough-clusters>What are BlackHole and Passthrough clusters?</h2><ul><li><strong>BlackHoleCluster</strong> - The BlackHoleCluster is a virtual cluster created
in the Envoy configuration when <code>global.outboundTrafficPolicy.mode</code> is set to
<code>REGISTRY_ONLY</code>. In this mode, all traffic to ex