# On Istio metrics reported by the destination proxy, which connection_security_policy value means the request used mutual TLS?

Istio, Easy (Beginner), Troubleshooting. https://k8wiz.com/uquiz/on-istio-metrics-reported-by-the-destination-proxy-which-connection_security_policy-value-means-the-request-used-mutual-tls

- A. mutual_tls
- B. istio_mutual
- C. strict
- D. mtls_enabled

**Answer:** mutual_tls

**Explanation:** Istio sets connection_security_policy to mutual_tls when the connection used Istio's mutual TLS and the destination reports the metric. Querying istio_requests_total for reporter="destination" and any other value finds the plain-text clients to fix before switching to STRICT. On metrics reported by the source the label is unknown.