ll fall back to treating the traffic as TCP, but you can easily <a href=/v1.19/docs/ops/configuration/traffic-management/protocol-selection/>annotate the service</a> with the traffic type.</p><p>Learn more about <a href=/v1.19/docs/ops/deployment/requirements/>enabling applications for use with Istio</a>.</p><h3 id=enabling-security>Enabling security</h3><p>Istio will configure services in the mesh to use mTLS when talking to one another when possible. Istio will run in &ldquo;permissive mTLS&rdquo; mode by