.io/docs/envoy/latest/intro/arch_overview/upstream/service_discovery#original-destination>original destination load balancing</a>
policy which configures Envoy to send the traffic to the
original destination i.e. passthrough.</p><p>Similar to the BlackHoleCluster, for every port/protocol based listener the
virtual route configuration is augmented to add the PassthroughCluster as the
default route:</p><pre><code class=language-json data-expandlinks=true data-repo=istio>{
  &#34;name&#34;: &#34;allow_any&#34;