pilot:
  env:
    # 1.21 behavioral changes
    ENABLE_EXTERNAL_NAME_ALIAS: "false"
    PERSIST_OLDEST_FIRST_HEURISTIC_FOR_VIRTUAL_SERVICE_HOST_MATCHING: "true"
    VERIFY_CERTIFICATE_AT_CLIENT: "false"
    ENABLE_AUTO_SNI: "false"

    # 1.22 behavioral changes
    ENABLE_RESOLUTION_NONE_TARGET_PORT: "false"

meshConfig:
  # 1.22 behavioral changes
  defaultConfig:
    proxyMetadata:
      ISTIO_DELTA_XDS: "false"

pilot:
  env:
    # 1.21 behavioral changes
    ENABLE_EXTERNAL_NAME_ALIAS: "false"
    PERSIST_OLDEST_FIRST_HEURISTIC_FOR_VIRTUAL_SERVICE_HOST_MATCHING: "true"
    VERIFY_CERTIFICATE_AT_CLIENT: "false"
    ENABLE_AUTO_SNI: "false"

    # 1.22 behavioral changes
    ENABLE_RESOLUTION_NONE_TARGET_PORT: "false"

meshConfig:
  # 1.22 behavioral changes
  defaultConfig:
    proxyMetadata:
      ISTIO_DELTA_XDS: "false"

  // secretName is the name of the secret used to terminate TLS traffic on
  // port 443. Field is left optional to allow TLS routing based on SNI
  // hostname alone. If the SNI host in a listener conflicts with the "Host"
  // header field used by an IngressRule, the SNI host is used for termination
  // and value of the "Host" header is used for routing.
  // +optional
  optional string secretName = 2;
}

    * This SNI extension allows one single server (with a **single IP address**) to have **several HTTPS certificates** and serve **multiple HTTPS domains/applications**.

pilot:
  env:
    # 1.21 behavioral changes
    ENABLE_EXTERNAL_NAME_ALIAS: "false"
    PERSIST_OLDEST_FIRST_HEURISTIC_FOR_VIRTUAL_SERVICE_HOST_MATCHING: "true"
    VERIFY_CERTIFICATE_AT_CLIENT: "false"
    ENABLE_AUTO_SNI: "false"

    # 1.22 behavioral changes
    ENABLE_RESOLUTION_NONE_TARGET_PORT: "false"

meshConfig:
  # 1.22 behavioral changes
  defaultConfig:
    proxyMetadata:
      ISTIO_DELTA_XDS: "false"
    tracing:

Currently, SNI is not set by Istio clients and ignored by Istio servers.
This makes identifying which certificate to use problematic for Ztunnel.
To handle this, requests to Ztunnel are sent to `DestinationPod:15008` and redirected to ztunnel, rather than `ZtunnelPod:15008`.
The original destination is then extracted to determined which certificate to use.

    - port: 80
      targetPort: 8080
      name: http2
    - port: 443
      targetPort: 8443
      name: https
    - port: 31400
      targetPort: 31400
      name: tcp
      # This is the port where sni routing happens
    - port: 15443
      targetPort: 15443
      name: tls
    resources:
      requests:
        cpu: 10m

pilot:
  env:
    # 1.21 behavioral changes
    ENABLE_EXTERNAL_NAME_ALIAS: "false"
    PERSIST_OLDEST_FIRST_HEURISTIC_FOR_VIRTUAL_SERVICE_HOST_MATCHING: "true"
    VERIFY_CERTIFICATE_AT_CLIENT: "false"
    ENABLE_AUTO_SNI: "false"

    # 1.22 behavioral changes
    ENABLE_RESOLUTION_NONE_TARGET_PORT: "false"

meshConfig:
  # 1.22 behavioral changes
  defaultConfig:
    proxyMetadata:
      ISTIO_DELTA_XDS: "false"

pilot:
  env:
    # 1.21 behavioral changes
    ENABLE_EXTERNAL_NAME_ALIAS: "false"
    PERSIST_OLDEST_FIRST_HEURISTIC_FOR_VIRTUAL_SERVICE_HOST_MATCHING: "true"
    VERIFY_CERTIFICATE_AT_CLIENT: "false"
    ENABLE_AUTO_SNI: "false"

    # 1.22 behavioral changes
    ENABLE_RESOLUTION_NONE_TARGET_PORT: "false"

meshConfig:
  # 1.22 behavioral changes
  defaultConfig:
    proxyMetadata:
      ISTIO_DELTA_XDS: "false"

     * 不过，对此有一个**解决方案**。
* **TLS** 协议（在 HTTP 之下的TCP 层处理加密的协议）有一个**扩展**，称为 **<a href="https://en.wikipedia.org/wiki/Server_Name_Indication" class="external-link" target="_blank"><abbr title="服务器名称指示">SNI</abbr></a>**。
     * SNI 扩展允许一台服务器（具有 **单个 IP 地址**）拥有 **多个 HTTPS 证书** 并提供 **多个 HTTPS 域名/应用程序**。
     * 为此，服务器上会有**单独**的一个组件（程序）侦听**公共 IP 地址**，这个组件必须拥有服务器中的**所有 HTTPS 证书**。
* **获得安全连接后**，通信协议**仍然是HTTP**。