Alibaba Cloud CDN follows the protocol specified by the origin protocol policy to retrieve resources from an origin server. After you configure the origin protocol policy, Alibaba Cloud CDN redirects HTTP requests to port 80 or HTTPS requests to port 443. The protocol that Alibaba Cloud CDN uses is determined by the origin protocol policy.

Background information

The origin protocol policy is disabled by default. Requests are redirected over the port specified in Basic Information > Origin Information.
  • If port 443 is used, requests are redirected to the origin server over HTTPS.
  • If port 80 or a custom port is used, requests are redirected to the origin server over HTTP.
Note The origin protocol policy supports only port 80 and port 443. After the origin protocol policy is enabled, the port specified in Origin Information becomes invalid. If you want CDN edge nodes to redirect requests to origin servers over a custom port, submit a ticket.

Procedure

  1. Log on to the Alibaba Cloud CDN console.
  2. In the left-side navigation pane, click Domain Names.
  3. On the Domain Names page, find the domain name that you want to manage and click Manage in the Actions column of the domain name.
  4. In the management pane of the domain name, click Back-to-origin.
  5. In the Origin Protocol Policy section, turn on Origin Protocol Policy.
  6. Click Modify.
  7. In the Static Origin Protocol Policy dialog box, set Redirect Type to Follow, HTTP, or HTTPS based on your business requirements.
    Static origin protocol policy
    Parameter Description
    Follow When a client sends an HTTP or an HTTPS request, Alibaba Cloud CDN redirects the request to the origin server over the protocol used by the client. Make sure that both port 443 and port 80 are open on the origin server. Otherwise, Alibaba Cloud CDN fails to redirect client requests to the origin server.
    Note The origin protocol policy protects data from tampering and eavesdropping during transmission. If you want to transmit sensitive data such as user identity data over HTTPS, and other data such as image files and video files over HTTP, we recommend that you set the origin protocol policy to Follow.
    HTTP Alibaba Cloud CDN redirects requests to the origin server only over HTTP.
    HTTPS Alibaba Cloud CDN redirects requests to the origin server only over HTTPS.
    Note
    • HTTPS encryption consumes additional computing resources on the origin server.
    • If you set the origin protocol policy to HTTPS, port 443 is used by default. If you want to use a custom port, submit a ticket.
  8. Click OK.